fix(ci): yoda condition + un-shadow capability-cache test expectations

- class-image-composer.php: swap the fingerprint comparison operands
  (WordPress.PHP.YodaConditions flagged the parenthesized null-coalesce
  expression on the right-hand side).
- ImageComposerTest: the two capability-cache tests asserted
  update_option calls via Functions\expect(), which the setUp
  Functions\when() stub shadows (Mockery dispatches the call to the
  first matching expectation), so the with()-matcher saw 0 calls once
  the CI runner's real imagick made the probe path live. Capture calls
  with a when() alias instead (the suite's house pattern) and assert on
  the captured writes - including autoload=false and the rewritten
  fingerprint. The matching-fingerprint test now genuinely asserts
  zero writes instead of a trivially-satisfied never().

No composer behavior change beyond the operand swap.

Agent-Session: engineer-prautoblogger-image-composer-20260611

.github/workflows/cto-review.yml

@@ -123,17 +123,18 @@ jobs:
           git fetch origin ${{ github.event.pull_request.base.ref }} --depth=50
           BASE_SHA="${{ github.event.pull_request.base.sha }}"
           HEAD_SHA="${{ github.event.pull_request.head.sha }}"
-          DIFF=$(git diff --no-color "$BASE_SHA" "$HEAD_SHA" | head -c 400000)
+          # Write the diff to a file, not a step output / env var. Passing a
+          # ~400KB diff through the process env (execve argv+envp) exceeds the
+          # runner ARG_MAX and fails the next step with "Argument list too long"
+          # (issue #110). File transport also sidesteps the ~1MB step-output cap.
+          git diff --no-color "$BASE_SHA" "$HEAD_SHA" | head -c 400000 > /tmp/cto-review-diff.txt
           FILES=$(git diff --name-only "$BASE_SHA" "$HEAD_SHA")
-          SIZE=$(echo -n "$DIFF" | wc -c)
+          SIZE=$(wc -c < /tmp/cto-review-diff.txt)
           {
             echo "size=$SIZE"
             echo "files<<EOF_FILES"
             echo "$FILES"
             echo "EOF_FILES"
-            echo "diff<<EOF_DIFF"
-            echo "$DIFF"
-            echo "EOF_DIFF"
           } >> "$GITHUB_OUTPUT"
 
       - name: Load repo conventions
@@ -161,7 +162,7 @@ jobs:
           PR_AUTHOR: ${{ github.event.pull_request.user.login }}
           PR_NUMBER: ${{ github.event.pull_request.number }}
           REPO_NAME: ${{ github.event.repository.name }}
-          DIFF: ${{ steps.diff.outputs.diff }}
+          DIFF_PATH: /tmp/cto-review-diff.txt
           DIFF_SIZE: ${{ steps.diff.outputs.size }}
           CHANGED_FILES: ${{ steps.diff.outputs.files }}
           CONVENTIONS: ${{ steps.conventions.outputs.content }}
@@ -229,7 +230,9 @@ jobs:
           user_blocks.append(f"**Changed files:**\n```\n{os.environ['CHANGED_FILES']}\n```\n")
           if os.environ.get("CONVENTIONS", "").strip():
               user_blocks.append(f"# Repo CONVENTIONS.md\n{os.environ['CONVENTIONS']}\n")
-          user_blocks.append(f"# Diff\n```diff\n{os.environ['DIFF']}\n```\n")
+          with open(os.environ["DIFF_PATH"], encoding="utf-8", errors="replace") as _df:
+              _diff_text = _df.read()
+          user_blocks.append(f"# Diff\n```diff\n{_diff_text}\n```\n")
           user_message = "\n\n".join(user_blocks)
 
           tools = [{

.github/workflows/deploy.yml

@@ -28,92 +28,10 @@ jobs:
             -not -path './.github/*' \
             -print0 | xargs -0 -n1 -P4 php -l > /dev/null
 
-  deploy-staging:
-    name: Deploy to Staging
+  deploy:
+    name: Deploy (shared pipeline)
     needs: validate
-    runs-on: ubuntu-latest
-    environment: staging
-    steps:
-      - uses: actions/checkout@v4
-      - name: Setup SSH key
-        run: |
-          mkdir -p ~/.ssh
-          echo "${{ secrets.SSH_PRIVATE_KEY }}" > ~/.ssh/deploy_key
-          chmod 600 ~/.ssh/deploy_key
-          ssh-keyscan -p ${{ secrets.SSH_PORT }} ${{ secrets.SSH_HOST }} >> ~/.ssh/known_hosts 2>/dev/null
-      - name: Deploy via rsync → staging
-        run: |
-          rsync -avz --delete \
-            --exclude '.git' --exclude '.github' \
-            --exclude 'tests' --exclude 'phpunit.xml.dist' \
-            --exclude 'composer.json' --exclude 'composer.lock' \
-            --exclude 'vendor' --exclude '.distignore' \
-            --exclude 'ARCHITECTURE.md' --exclude 'CONVENTIONS.md' \
-            -e "ssh -i ~/.ssh/deploy_key -p ${{ secrets.SSH_PORT }}" \
-            ./ ${{ secrets.SSH_USERNAME }}@${{ secrets.SSH_HOST }}:~/domains/peptiderepo.com/public_html/staging/wp-content/plugins/prautoblogger/
-      - name: Staging health check
-        run: |
-          sleep 5
-          STATUS=$(curl -s -o /dev/null -w "%{http_code}" https://staging.peptiderepo.com/ || echo "000")
-          echo "Staging responded: HTTP $STATUS"
-          [ "$STATUS" = "000" ] && echo "Warning: staging DNS may still be propagating" || true
-      - name: Cleanup
-        if: always()
-        run: rm -f ~/.ssh/deploy_key
-
-  smoke:
-    name: Smoke tests (staging)
-    needs: deploy-staging
-    continue-on-error: true
-    uses: peptiderepo/peptide-e2e/.github/workflows/smoke.yml@main
-    secrets:
-      STAGING_WP_ADMIN_USER: ${{ secrets.STAGING_WP_ADMIN_USER }}
-      STAGING_WP_ADMIN_PASSWORD: ${{ secrets.STAGING_WP_ADMIN_PASSWORD }}
-
-  deploy-production:
-    name: Deploy to Production
-    needs: [validate, deploy-staging]
-    runs-on: ubuntu-latest
-    environment: production
-    steps:
-      - uses: actions/checkout@v4
-      - name: Setup SSH key
-        run: |
-          mkdir -p ~/.ssh
-          echo "${{ secrets.SSH_PRIVATE_KEY }}" > ~/.ssh/deploy_key
-          chmod 600 ~/.ssh/deploy_key
-          ssh-keyscan -p ${{ secrets.SSH_PORT }} ${{ secrets.SSH_HOST }} >> ~/.ssh/known_hosts 2>/dev/null
-      - name: Deploy via rsync → production
-        run: |
-          rsync -avz --delete \
-            --exclude '.git' --exclude '.github' \
-            --exclude 'tests' --exclude 'phpunit.xml.dist' \
-            --exclude 'composer.json' --exclude 'composer.lock' \
-            --exclude 'vendor' --exclude '.distignore' \
-            --exclude 'ARCHITECTURE.md' --exclude 'CONVENTIONS.md' \
-            -e "ssh -i ~/.ssh/deploy_key -p ${{ secrets.SSH_PORT }}" \
-            ./ ${{ secrets.SSH_USERNAME }}@${{ secrets.SSH_HOST }}:~/domains/peptiderepo.com/public_html/wp-content/plugins/prautoblogger/
-      - name: Purge LiteSpeed Cache
-        run: |
-          ssh -i ~/.ssh/deploy_key -p ${{ secrets.SSH_PORT }} \
-            ${{ secrets.SSH_USERNAME }}@${{ secrets.SSH_HOST }} \
-            "cd ~/domains/peptiderepo.com/public_html && \
-             wp litespeed-purge all 2>/dev/null || \
-             (find wp-content/litespeed/ -type f -delete 2>/dev/null; touch .lscache_purge 2>/dev/null) || true"
-      - name: Production health check
-        run: |
-          sleep 5
-          STATUS=$(curl -s -o /dev/null -w "%{http_code}" https://peptiderepo.com)
-          if [ "$STATUS" != "200" ] && [ "$STATUS" != "403" ]; then
-            echo "ERROR: Site returned unexpected HTTP $STATUS after deploy"
-            exit 1
-          fi
-          echo "Production healthy (HTTP $STATUS)"
-      - name: Cleanup
-        if: always()
-        run: rm -f ~/.ssh/deploy_key
-      - name: Deploy summary
-        run: |
-          echo "## Deployment Complete" >> $GITHUB_STEP_SUMMARY
-          echo "- **Commit:** \`${GITHUB_SHA::7}\`" >> $GITHUB_STEP_SUMMARY
-          echo "- **Deployed to:** peptiderepo.com" >> $GITHUB_STEP_SUMMARY
+    uses: peptiderepo/peptide-e2e/.github/workflows/deploy-app.yml@main
+    with:
+      target_path: wp-content/plugins/prautoblogger
+    secrets: inherit

.github/workflows/main-push-audit.yml

@@ -29,12 +29,22 @@ jobs:
         with:
           script: |
             const sha = context.sha;
-            const { data: prs } = await github.rest.repos.listPullRequestsAssociatedWithCommit({
-              owner: context.repo.owner,
-              repo: context.repo.repo,
-              commit_sha: sha,
-            });
-            const merged = prs.find(p => p.merged_at);
+            // Squash-merge -> PR association is eventually-consistent; poll briefly
+            // before concluding this was a direct push (avoids false positives on merges).
+            async function findMergedPR() {
+              for (let attempt = 1; attempt <= 5; attempt++) {
+                const { data: prs } = await github.rest.repos.listPullRequestsAssociatedWithCommit({
+                  owner: context.repo.owner,
+                  repo: context.repo.repo,
+                  commit_sha: sha,
+                });
+                const m = prs.find(p => p.merged_at);
+                if (m) return m;
+                if (attempt < 5) await new Promise(r => setTimeout(r, 10000));
+              }
+              return null;
+            }
+            const merged = await findMergedPR();
             if (merged) {
               core.info(`OK: commit ${sha.substring(0,7)} came from PR #${merged.number}`);
               return;

ARCHITECTURE.md

@@ -75,6 +75,11 @@ PRAutoBlogger is a WordPress plugin that monitors social media (starting with Re
 │                         │  retried once with a rule-based fallback
 │                         │  prompt via Image_NSFW_Retry; a second block
 │                         │  logs WARNING and publishes without that image.
+│                         │  v0.17.0: results then pass through the local
+│                         │  deterministic Image_Composer (corner mark +
+│                         │  branded OG/square variants for Image A; mark
+│                         │  only for Image B) with a capability ladder
+│                         │  (imagick → GD resize-only → pass-through).
 │                         │  Sideloads to media library, logs costs.
 └────────────┬────────────┘
              │
@@ -103,6 +108,15 @@ prautoblogger/
 ├── CHANGELOG.md                       # Semantic versioning changelog
 │
 ├── assets/
+│   ├── brand/                         # Vendored brand PNGs rasterized from peptide-repo-brand SVGs (composer overlays)
+│   │   ├── logo-mark-small-56.png     # Corner mark, 1x
+│   │   ├── logo-mark-small-112.png    # Corner mark / OG band logo, 2x
+│   │   ├── logo-horizontal-reverse-128.png # Square footer lockup, 1x
+│   │   └── logo-horizontal-reverse-256.png # Square footer lockup, 2x
+│   ├── fonts/                         # Bundled OFL faces for deterministic text rendering
+│   │   ├── Poppins-Bold.ttf           # Square-card caption face
+│   │   ├── Poppins-SemiBold.ttf       # OG band caption face
+│   │   └── OFL.txt                    # SIL Open Font License
 │   ├── css/
 │   │   ├── admin.css                  # Admin page styles (wp-admin conventions)
 │   │   └── posts-widget.css           # Frontend posts widget styles (uses theme CSS vars)
@@ -147,6 +161,14 @@ prautoblogger/
 │   │   ├── class-post-assembler.php   # Post-creation helpers: taxonomy, log linking, images, sanitization
 │   │   ├── class-image-pipeline.php   # Orchestrates A/B image generation (parallel via batch)
 │   │   ├── class-image-prompt-builder.php # Generates visual prompts from article/source data
+│   │   ├── class-image-template-filler.php # Fills the editorial style template's {{ topic_summary }} slot (v0.16.0)
+│   │   ├── interface-image-composer.php    # Contract: provider bytes → featured-first variant list (v0.17.0)
+│   │   ├── class-image-composer.php        # Composer orchestrator: cached capability probe + degradation ladder
+│   │   ├── class-image-composer-imagick.php # Imagick renderer: corner mark, OG band, square card (WP-free)
+│   │   ├── class-image-composer-canvas.php # Imagick primitives: smoke test, cover-crop, logo, deterministic PNG (WP-free)
+│   │   ├── class-image-composer-editor.php # Resize-only rung via wp_get_image_editor (GD path)
+│   │   ├── class-image-composer-layout.php # Geometry defaults + caption clamp (pure, WP-free)
+│   │   ├── class-image-attacher.php        # Sideload + cost log + variant meta-linking + caption prepend
 │   │   ├── class-image-media-sideloader.php # Imports images into WordPress media library
 │   │   ├── class-cost-tracker.php     # Logs all API costs, enforces budget limits
 │   │   ├── class-logger.php           # Structured logging singleton (error/warning/info/debug)
@@ -437,15 +459,20 @@ All prefixed with `prautoblogger_`:
 | `prautoblogger_schedule_time`          | Daily generation time (HH:MM, default: '03:00')       |
 | `prautoblogger_image_model`            | Image model slug from `Image_Model_Registry::get_models()`; provider is derived from this on save |
 | `prautoblogger_image_provider`         | Derived from the chosen model on save (v0.8.0+); not editable in admin UI |
-| `prautoblogger_image_prompt_instructions` | System prompt given to the image rewriter LLM (v0.8.0+); falls back to `Image_Prompt_Builder::REWRITER_SYSTEM_PROMPT` when empty |
+| `prautoblogger_image_prompt_instructions` | System prompt given to the image rewriter LLM (v0.8.0+); falls back to `Image_Prompt_Builder::REWRITER_SYSTEM_PROMPT` when empty. v0.16.0: the default now instructs the LLM to emit a 1-2 sentence editorial topic/mechanism summary as the SCENE (was a comic gag) |
 | `prautoblogger_image_nsfw_retry`       | Toggle: retry NSFW-blocked image slots with a rule-based fallback prompt (default: '1') |
 | `prautoblogger_migrated_image_provider_v080` | One-shot migration flag — auto-heals mismatched provider/model pairs on first admin_init after v0.8.0 upgrade |
 | `prautoblogger_article_font_family`    | Font family key: 'default', 'inter', 'georgia', 'merriweather', 'lora', 'open_sans', 'roboto', 'system' |
 | `prautoblogger_article_font_size`     | Body font size in px (0 = theme default). Recommended: 16–18. |
 | `prautoblogger_table_borders`         | Toggle: add borders/padding/striping to tables (default: '1') |
-| `prautoblogger_image_style_suffix`     | Text appended to every image prompt (default: CEO-locked 90s infomercial prompt) |
+| `prautoblogger_image_style_template`   | Full image prompt template (v0.16.0+); contains exactly one `{{ topic_summary }}` token filled per-article with the rewriter scene. Default = `PRAUTOBLOGGER_DEFAULT_IMAGE_STYLE_TEMPLATE` (editorial scientific illustration). Replaces the Style Suffix. Validated on save (single-token, brief A5) |
+| `prautoblogger_image_style_suffix`     | DEPRECATED (v0.16.0). Former comic style suffix appended to every image prompt; no longer read by the builder. Mirrored to `prautoblogger_image_style_suffix_deprecated` for one cycle and not deleted yet |
 | `prautoblogger_openrouter_model_registry` | Normalized OpenRouter model list (JSON array, daily refresh, serves as durable cache) |
 | `prautoblogger_openrouter_model_registry_fetched_at` | Unix timestamp of last successful model registry refresh |
+| `prautoblogger_image_compose_enabled`  | Toggle: run the deterministic image composer (default '1'; auto-degrades, never blocks publishing) |
+| `prautoblogger_image_compose_variants` | Comma list of composed variants for Image A (default 'og,square'; whitelisted at point of use) |
+| `prautoblogger_image_featured_mark_enabled` | Toggle: subtle corner mark on featured images (default '1') |
+| `prautoblogger_image_compose_capability` | Cached capability probe `{fingerprint, capability}`; fingerprint = PHP version + imagick/gd presence, so it auto-invalidates on host changes |
 
 ### Post Meta
 
@@ -464,6 +491,14 @@ Stored on every PRAutoBlogger-generated post:
 | `_prautoblogger_editor_notes`         | Chief editor's review notes                   |
 | `_prautoblogger_generated_at`         | ISO 8601 timestamp of generation              |
 | `_prautoblogger_research_sources`     | JSON array of source URLs used                |
+| `_prautoblogger_og_image_id`          | Attachment ID of the composed 1200×630 OG variant (v0.17.0; the rebuilt SEO stage emits `og:image` from this — key name frozen) |
+| `_prautoblogger_square_image_id`      | Attachment ID of the composed 1080×1080 square variant (v0.17.0; stored now, no consumer yet) |
+
+Composed-variant **attachment** meta (v0.17.0): every pipeline attachment gets
+`_prautoblogger_image_role` (`featured`/`og`/`square`); OG/square variants also
+get `_prautoblogger_base_attachment_id` pointing at the featured attachment
+they derive from. All keys keep the `_prautoblogger_` prefix, so the uninstall
+prefix-sweep purges them.
 
 ---
 
@@ -575,6 +610,52 @@ Reddit rejected our OAuth API application (April 2026). We initially switched to
 
 The admin model picker (v1) needs to list OpenRouter models with pricing and capabilities. We fetch `https://openrouter.ai/api/v1/models` (free, unauthenticated) once daily and store the normalized payload in a WP option fronted by a 24h transient. On stale-and-fetch-fails, we serve last-good + surface a warning. The registry class (`class-open-router-model-registry.php`) takes all config via constructor (option name, transient name, endpoint URL) — no PRAUTOBLOGGER_* constants inside the class body. Phase 2 lifts it into a shared Composer package with zero internal edits. Phase 3 adds a parallel `Cloudflare_WorkersAI_Model_Registry` behind the same interface. Capability vocabulary: `text→text`, `text+image→text`, `text+audio→text`, `text→image`, `text→audio`, `text→video`, `text→embedding`. Cost: $0/month.
 
+### #20: Editorial illustration prompt + style-template setting (v0.16.0, May 2026)
+
+Commit 1 of the in-plugin editorial image pipeline (brief `docs/proposals/2026-05-29-image-pipeline-in-plugin-brief.md`). The image style pivots from a single-panel newspaper comic to a **text-free editorial scientific illustration**. Two changes ship here; the deterministic PHP composer is a later commit.
+
+1. **Prompt structure.** `Image_Prompt_Builder::REWRITER_SYSTEM_PROMPT` now asks the rewriter LLM for a concise 1-2 sentence topic/mechanism summary (one concrete centered focal subject, no text/people-as-gag/logos) as the SCENE, keeping the short CAPTION line for the unchanged HTML-caption-below-image path. The scene/caption parsing contract (`Image_Scene_Parser`) is unchanged.
+2. **Template substitution.** The old `trim($scene . ' ' . $style_suffix)` concat is replaced by `PRAutoBlogger_Image_Template_Filler::fill($scene)` in all three entry points (`build_article_prompt`, `build_source_prompt`, `build_fallback_prompt`). The filler resolves the active template (admin override → default), strips control chars and clamps the summary length (brief A5), then substitutes the single `{{ topic_summary }}` token. Degradation (brief A5/A6): if the template lacks exactly one token it appends the summary and logs a warning; if the summary is empty it emits the style-only prompt — a blank or token-only prompt is never sent to the provider.
+3. **Setting.** New textarea `prautoblogger_image_style_template` (default `PRAUTOBLOGGER_DEFAULT_IMAGE_STYLE_TEMPLATE`) replaces the Style Suffix field. On save it is sanitised with `sanitize_textarea_field` and validated to contain exactly one token (`Image_Template_Filler::sanitize_for_save`). The old `prautoblogger_image_style_suffix` is mirrored to `..._deprecated` for one cycle and not deleted (one-time migration `prautoblogger_migrated_style_template_v0160`).
+
+Provider/model are unchanged — only the prompt text changes, so production keeps emitting via Runware FLUX.1 schnell but now produces text-free editorial base images.
+
+### #21: Deterministic PHP image composer with capability ladder (v0.17.0, Jun 2026)
+
+Commit 2 (and final scope) of the in-plugin editorial image pipeline (#20). Small diffusion
+models cannot render clean text (2026-04-21 A/B finding), so base images are text-free —
+but the one image that travels *without* its HTML caption is the social/OG share image.
+A **deterministic local composer** (`PRAutoBlogger_Image_Composer` behind
+`PRAutoBlogger_Image_Composer_Interface`) now runs between provider bytes and sideload:
+
+1. **Variants.** Image A → corner-marked featured (1200×632) + branded OG (1200×630, teal
+   band, brand mark, baked caption in Poppins SemiBold) + square card (1080×1080: full base
+   downscaled into a 1080×569 top slice — no upscaling — cream caption panel in Poppins
+   Bold, teal footer with the horizontal reverse lockup). Image B → corner mark only. The
+   variant set is config-driven (`prautoblogger_image_compose_variants`, default `og,square`;
+   square has no consumer yet — CEO wants it rendered + stored now). Variants are
+   meta-linked via `_prautoblogger_image_role`, `_prautoblogger_base_attachment_id`,
+   `_prautoblogger_og_image_id`, `_prautoblogger_square_image_id`. The og key is **frozen**:
+   the rebuilt SEO stage (pipeline-redesign §4.8) emits `og:image` from it.
+2. **Capability ladder, never fatal.** Imagick is probed once (PNG format + TTF annotate
+   smoke test) and cached in `prautoblogger_image_compose_capability`, fingerprinted by
+   PHP version + imagick/gd presence so host flips (hPanel/cagefs — it has happened)
+   auto-invalidate the cache. Rungs: imagick → `wp_get_image_editor()` resize-only
+   (unbranded, square skipped because it would upscale) → pass-through. Every render is
+   try/caught; degradation logs one WARNING per run; the publish always proceeds with the
+   editable HTML caption intact. Test/ops override: `prautoblogger_image_compose_capability`
+   filter.
+3. **Determinism.** Bundled OFL fonts (no system-font queries), vendored brand PNGs (no
+   runtime SVG delegate variance), `stripImage()` + PNG date/time chunks excluded + fixed
+   compression → byte-stable output **per environment** (not across ImageMagick versions).
+   Composition is local CPU, $0, logged as a duration-only stage on the `image_composer`
+   channel — no cost-tracker rows.
+4. **Layout tuning.** Geometry/opacity are constants in
+   `PRAutoBlogger_Image_Composer_Layout::defaults()` behind the
+   `prautoblogger_image_compose_layout` filter — deliberately not settings; promote only if
+   the CEO asks to tune them. The caption is hard-clamped (word-boundary wrap + ellipsis,
+   multibyte-safe) even though the rewriter LLM is already constrained to <15 words.
+
 ### #17: Runware as default image backend (v0.9.0, Apr 2026)
 
 After a comic-style A/B round in Apr 2026, FLUX.1 schnell via Runware was chosen as the default image backend. Cost is ~$0.0006/image vs ~$0.039/image for Gemini 2.5 Flash Image via OpenRouter (≈65× cheaper), and the looser schnell fidelity reads as editorial-cartoon style — a feature, not a bug, for our single-panel comic aesthetic. FLUX.1 dev (~$0.02/image, 28 steps) remains available as an opt-in for higher-fidelity runs. The Runware layer mirrors the OpenRouter split (interface + provider + support + pricing + batch), all under the 300-line cap. The batch class dispatches `imageInference` POSTs via `curl_multi_init/exec/select` — wall-clock time for the A/B pair drops to ≈ the slowest single image. A v0.9.0 one-time migration (`prautoblogger_migrated_default_image_v090`) flips sites still on the legacy default; explicit user selections are preserved. Cloudflare Workers AI was removed as an image provider in v0.10.0 (see ADR #16 note below).

CHANGELOG.md

@@ -5,6 +5,91 @@ All notable changes to PRAutoBlogger will be documented in this file.
 Format follows [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 and this project uses [Semantic Versioning](https://semver.org/).
 
+## [0.17.0] - 2026-06-11
+
+### Added
+- **Deterministic PHP image composer (Commit 2 of the in-plugin editorial image
+  pipeline).** Every generated image now passes through a local, $0,
+  deterministic composer between the provider's bytes and the media sideloader.
+  Image A yields a corner-marked featured image (1200×632) plus a branded
+  **OG/social variant** (1200×630, teal band, brand mark, baked editorial
+  caption in Poppins SemiBold) and a **square card variant** (1080×1080, image
+  slice + cream caption panel in Poppins Bold + teal footer with the horizontal
+  lockup). Image B gets the corner mark only. Variants are sideloaded with a
+  role filename suffix and meta-linked: attachment meta
+  `_prautoblogger_image_role` + `_prautoblogger_base_attachment_id`, post meta
+  `_prautoblogger_og_image_id` + `_prautoblogger_square_image_id` (the rebuilt
+  SEO stage will emit `og:image` from the frozen og key).
+- **Capability ladder with cached probe.** Imagick (full compositing) →
+  `wp_get_image_editor()` GD path (resize-only, unbranded, single WARNING) →
+  pass-through (single WARNING). The probe result is cached in
+  `prautoblogger_image_compose_capability`, fingerprinted by PHP version +
+  imagick/gd presence so it auto-invalidates when the host changes. Override
+  filter: `prautoblogger_image_compose_capability`. Composition failure can
+  never block a publish (per-render try/catch + pipeline safety net).
+- New Images settings: `prautoblogger_image_compose_enabled` (default on),
+  `prautoblogger_image_compose_variants` (default `og,square`),
+  `prautoblogger_image_featured_mark_enabled` (default on). Geometry ships as
+  layout-class constants behind the `prautoblogger_image_compose_layout`
+  filter. All keys keep the `prautoblogger_`/`_prautoblogger_` prefixes, so
+  the existing uninstall prefix-sweep purges them (no uninstall.php changes).
+- Vendored brand rasters (`assets/brand/`, from peptide-repo-brand SVG masters)
+  and bundled OFL fonts (`assets/fonts/`: Poppins Bold + Poppins SemiBold +
+  OFL.txt) — no system-font or runtime-SVG dependency, byte-stable output per
+  environment (metadata stripped, PNG date/time chunks excluded).
+
+### Fixed
+- Featured/Image B **alt text is now the editorial caption** instead of the
+  generation model name (`sideload_and_log()` passed the model as `$alt_text`,
+  contradicting the sideloader docblock). The model keeps persisting in
+  `_prautoblogger_image_model`.
+
+### Changed
+- `PRAutoBlogger_Image_Media_Sideloader::sideload_image()` /
+  `generate_filename()` accept an optional filename role suffix
+  (back-compat default `''`).
+- `PRAutoBlogger_Image_Pipeline` delegates sideload/cost-log, caption
+  prepending, and variant persistence to the new
+  `PRAutoBlogger_Image_Attacher` (300-line compliance); also declares the
+  previously-dynamic `$trace_context` property (PHP 8.2 deprecation).
+
+## [0.16.0] - 2026-05-29
+
+### Changed
+- **Editorial image prompt (Commit 1 of the in-plugin editorial image pipeline).**
+  The image style pivots from a single-panel newspaper comic to a text-free
+  editorial scientific illustration. The rewriter LLM now emits a concise
+  1-2 sentence topic/mechanism summary as the SCENE (one centered focal
+  subject, no text/people-as-gag/logos), keeping the short CAPTION line for the
+  unchanged HTML-caption-below-image behavior. The scene/caption parsing
+  contract is unchanged. Provider/model are unchanged — production keeps
+  generating via Runware FLUX.1 schnell but now produces text-free editorial
+  base images. See `docs/proposals/2026-05-29-image-pipeline-in-plugin-brief.md`.
+- The prompt builder now substitutes the rewriter scene into an editable style
+  template's `{{ topic_summary }}` slot via the new
+  `PRAutoBlogger_Image_Template_Filler`, replacing the old
+  `scene + style suffix` concatenation, across all three entry points
+  (`build_article_prompt`, `build_source_prompt`, `build_fallback_prompt`).
+  Before substitution the scene is stripped of control characters and
+  length-clamped (brief A5). If the template lacks exactly one token the
+  summary is appended and a warning logged; if the summary is empty the
+  style-only prompt is emitted — a blank or token-only prompt is never sent to
+  the provider (brief A5/A6).
+
+### Added
+- New setting **Style Template** (`prautoblogger_image_style_template`,
+  textarea) replacing the Style Suffix field. Default =
+  `PRAUTOBLOGGER_DEFAULT_IMAGE_STYLE_TEMPLATE` (the editorial template). On save
+  it is validated to contain exactly one `{{ topic_summary }}` token; an invalid
+  template keeps the previous value and surfaces a settings error.
+
+### Deprecated
+- `prautoblogger_image_style_suffix` is deprecated and no longer read by the
+  prompt builder. A one-time migration (`prautoblogger_migrated_style_template_v0160`)
+  mirrors its value to `prautoblogger_image_style_suffix_deprecated` for one
+  version cycle and seeds the new template default. The old option is NOT
+  deleted this cycle.
+
 ## [0.15.1] - 2026-05-14
 
 ### Fixed

CONVENTIONS.md

@@ -150,6 +150,38 @@ interface PRAutoBlogger_Image_Provider_Interface {
 
 ---
 
+## How To: Tune the Image Composer (v0.17.0+)
+
+The deterministic composer (ARCHITECTURE.md #21) renders branded variants between
+provider bytes and sideload. Three rules when touching it:
+
+1. **Geometry lives in code, not settings.** All sizes/colors/opacities come from
+   `PRAutoBlogger_Image_Composer_Layout::defaults()` and can be overridden via the
+   `prautoblogger_image_compose_layout` filter:
+   ```php
+   add_filter( 'prautoblogger_image_compose_layout', function ( array $layout ): array {
+       $layout['featured']['mark_opacity'] = 0.40;
+       return $layout;
+   } );
+   ```
+   Promote a value to a settings field only on explicit CEO request.
+2. **Keep renderer classes WP-free.** `Image_Composer_Imagick`, `Image_Composer_Canvas`,
+   and `Image_Composer_Layout` must not call WordPress functions — they are exercised by
+   a standalone render harness (and the determinism test) without a WP bootstrap. Only
+   the orchestrator (`Image_Composer`) and the GD rung (`Image_Composer_Editor`) may
+   touch WP APIs.
+3. **Never fatal a publish.** Any new render path needs a try/catch that degrades to
+   pass-through and logs at most one WARNING per run (`warn_once()`). Capability checks
+   go through the cached probe (`prautoblogger_image_compose_capability` option +
+   same-named override filter) — never re-probe per image.
+
+Adding a new variant role: extend `Layout::defaults()` + the renderer, whitelist the
+role in `Image_Composer::configured_variants()` and in
+`Image_Attacher::ROLE_POST_META` (new `_prautoblogger_{role}_image_id` post meta keeps
+the uninstall prefix-sweep effective), then cover it in the unit ladder tests.
+
+---
+
 ## How To: Add a New Admin Setting
 
 1. Define the option key in the settings array in `admin/class-admin-page.php` → `get_settings_fields()` method

assets/fonts/OFL.txt

@@ -0,0 +1,93 @@
+Copyright 2020 The Poppins Project Authors (https://github.com/itfoundry/Poppins)
+
+This Font Software is licensed under the SIL Open Font License, Version 1.1.
+This license is copied below, and is also available with a FAQ at:
+http://scripts.sil.org/OFL
+
+
+-----------------------------------------------------------
+SIL OPEN FONT LICENSE Version 1.1 - 26 February 2007
+-----------------------------------------------------------
+
+PREAMBLE
+The goals of the Open Font License (OFL) are to stimulate worldwide
+development of collaborative font projects, to support the font creation
+efforts of academic and linguistic communities, and to provide a free and
+open framework in which fonts may be shared and improved in partnership
+with others.
+
+The OFL allows the licensed fonts to be used, studied, modified and
+redistributed freely as long as they are not sold by themselves. The
+fonts, including any derivative works, can be bundled, embedded, 
+redistributed and/or sold with any software provided that any reserved
+names are not used by derivative works. The fonts and derivatives,
+however, cannot be released under any other type of license. The
+requirement for fonts to remain under this license does not apply
+to any document created using the fonts or their derivatives.
+
+DEFINITIONS
+"Font Software" refers to the set of files released by the Copyright
+Holder(s) under this license and clearly marked as such. This may
+include source files, build scripts and documentation.
+
+"Reserved Font Name" refers to any names specified as such after the
+copyright statement(s).
+
+"Original Version" refers to the collection of Font Software components as
+distributed by the Copyright Holder(s).
+
+"Modified Version" refers to any derivative made by adding to, deleting,
+or substituting -- in part or in whole -- any of the components of the
+Original Version, by changing formats or by porting the Font Software to a
+new environment.
+
+"Author" refers to any designer, engineer, programmer, technical
+writer or other person who contributed to the Font Software.
+
+PERMISSION & CONDITIONS
+Permission is hereby granted, free of charge, to any person obtaining
+a copy of the Font Software, to use, study, copy, merge, embed, modify,
+redistribute, and sell modified and unmodified copies of the Font
+Software, subject to the following conditions:
+
+1) Neither the Font Software nor any of its individual components,
+in Original or Modified Versions, may be sold by itself.
+
+2) Original or Modified Versions of the Font Software may be bundled,
+redistributed and/or sold with any software, provided that each copy
+contains the above copyright notice and this license. These can be
+included either as stand-alone text files, human-readable headers or
+in the appropriate machine-readable metadata fields within text or
+binary files as long as those fields can be easily viewed by the user.
+
+3) No Modified Version of the Font Software may use the Reserved Font
+Name(s) unless explicit written permission is granted by the corresponding
+Copyright Holder. This restriction only applies to the primary font name as
+presented to the users.
+
+4) The name(s) of the Copyright Holder(s) or the Author(s) of the Font
+Software shall not be used to promote, endorse or advertise any
+Modified Version, except to acknowledge the contribution(s) of the
+Copyright Holder(s) and the Author(s) or with their explicit written
+permission.
+
+5) The Font Software, modified or unmodified, in part or in whole,
+must be distributed entirely under this license, and must not be
+distributed under any other license. The requirement for fonts to
+remain under this license does not apply to any document created
+using the Font Software.
+
+TERMINATION
+This license becomes null and void if any of the above conditions are
+not met.
+
+DISCLAIMER
+THE FONT SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO ANY WARRANTIES OF
+MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT
+OF COPYRIGHT, PATENT, TRADEMARK, OR OTHER RIGHT. IN NO EVENT SHALL THE
+COPYRIGHT HOLDER BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
+INCLUDING ANY GENERAL, SPECIAL, INDIRECT, INCIDENTAL, OR CONSEQUENTIAL
+DAMAGES, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+FROM, OUT OF THE USE OR INABILITY TO USE THE FONT SOFTWARE OR FROM
+OTHER DEALINGS IN THE FONT SOFTWARE.

includes/admin/class-admin-page.php

@@ -330,6 +330,11 @@ class PRAutoBlogger_Admin_Page {
 		if ( 'prautoblogger_image_model' === $option_name ) {
 			return $this->sanitize_image_model( (string) $value );
 		}
+		if ( 'prautoblogger_image_style_template' === $option_name ) {
+			// Multi-line template: validation + textarea-safe sanitisation
+			// (incl. the single-token check, brief A5) lives in the filler.
+			return PRAutoBlogger_Image_Template_Filler::sanitize_for_save( (string) $value );
+		}
 		return sanitize_text_field( (string) $value );
 	}
 

includes/admin/class-settings-fields-extended.php

@@ -8,7 +8,7 @@ declare(strict_types=1);
  *
  * What: Declarative field definitions for operational settings sections.
  * Who calls it: PRAutoBlogger_Settings_Fields::get_fields() merges these in.
- * Dependencies: PRAUTOBLOGGER_DEFAULT_IMAGE_MODEL, PRAUTOBLOGGER_DEFAULT_IMAGE_STYLE_SUFFIX constants,
+ * Dependencies: PRAUTOBLOGGER_DEFAULT_IMAGE_MODEL, PRAUTOBLOGGER_DEFAULT_IMAGE_STYLE_TEMPLATE constants,
  *               PRAutoBlogger_Article_Typography (font choices), PRAutoBlogger_Image_Model_Registry.
  *
  * @see admin/class-settings-fields.php       — Core fields and sections; calls get_extended_fields().
@@ -235,12 +235,12 @@ class PRAutoBlogger_Settings_Fields_Extended {
 				'icon'        => '🔑',
 			),
 			array(
-				'id'          => 'prautoblogger_image_style_suffix',
-				'label'       => __( 'Style Suffix', 'prautoblogger' ),
+				'id'          => 'prautoblogger_image_style_template',
+				'label'       => __( 'Style Template', 'prautoblogger' ),
 				'type'        => 'textarea',
 				'section'     => 'prautoblogger_images',
-				'default'     => PRAUTOBLOGGER_DEFAULT_IMAGE_STYLE_SUFFIX,
-				'description' => __( 'Appended to every image prompt. Controls visual look. Changing mid-run causes visible style drift.', 'prautoblogger' ),
+				'default'     => PRAUTOBLOGGER_DEFAULT_IMAGE_STYLE_TEMPLATE,
+				'description' => __( 'The full image prompt template. Must contain exactly one {{ topic_summary }} token, which is filled with a 1-2 sentence topic/mechanism summary per article. The rest is brand-locked editorial style. Replaces the old Style Suffix (now deprecated). Changing mid-run causes visible style drift.', 'prautoblogger' ),
 			),
 			array(
 				'id'          => 'prautoblogger_image_prompt_instructions',
@@ -248,7 +248,7 @@ class PRAutoBlogger_Settings_Fields_Extended {
 				'type'        => 'textarea',
 				'section'     => 'prautoblogger_images',
 				'default'     => PRAutoBlogger_Image_Prompt_Builder::REWRITER_SYSTEM_PROMPT,
-				'description' => __( 'System prompt given to the rewriter LLM that turns each article into a SCENE + CAPTION for the image generator. Changing this reshapes the look of all future images. Leave blank to use the default.', 'prautoblogger' ),
+				'description' => __( 'System prompt given to the rewriter LLM that turns each article into a SCENE (a 1-2 sentence editorial topic/mechanism summary, substituted into the Style Template) plus a CAPTION (HTML text shown below the image). Changing this reshapes the look of all future images. Leave blank to use the default.', 'prautoblogger' ),
 			),
 			array(
 				'id'          => 'prautoblogger_image_nsfw_retry',
@@ -258,6 +258,30 @@ class PRAutoBlogger_Settings_Fields_Extended {
 				'default'     => '1',
 				'description' => __( 'When the provider rejects an image prompt as NSFW, retry once with a generic fallback scene built from the article title. Disable to fail fast if the filter gets trigger-happy.', 'prautoblogger' ),
 			),
+			array(
+				'id'          => 'prautoblogger_image_compose_enabled',
+				'label'       => __( 'Compose Branded Variants', 'prautoblogger' ),
+				'type'        => 'toggle',
+				'section'     => 'prautoblogger_images',
+				'default'     => '1',
+				'description' => __( 'Render branded social variants (teal band, logo, baked caption) from each generated image via the local deterministic composer. Auto-degrades to plain resizing or pass-through if the server lacks an image library — publishing is never blocked.', 'prautoblogger' ),
+			),
+			array(
+				'id'          => 'prautoblogger_image_compose_variants',
+				'label'       => __( 'Composed Variant Set', 'prautoblogger' ),
+				'type'        => 'text',
+				'section'     => 'prautoblogger_images',
+				'default'     => 'og,square',
+				'description' => __( 'Comma-separated variants to render for Image A. Supported: og (1200×630 social share), square (1080×1080 card). Unknown values are ignored.', 'prautoblogger' ),
+			),
+			array(
+				'id'          => 'prautoblogger_image_featured_mark_enabled',
+				'label'       => __( 'Featured Image Corner Mark', 'prautoblogger' ),
+				'type'        => 'toggle',
+				'section'     => 'prautoblogger_images',
+				'default'     => '1',
+				'description' => __( 'Overlay a small semi-transparent Peptide Repo mark in the bottom-right corner of featured images, so scraped or re-shared images carry attribution.', 'prautoblogger' ),
+			),
 			array(
 				'id'          => 'prautoblogger_runware_model_catalog',
 				'label'       => __( 'Runware Model Catalog', 'prautoblogger' ),

includes/class-prautoblogger.php

@@ -267,6 +267,24 @@ class PRAutoBlogger {
 			update_option( 'prautoblogger_migrated_style_suffix_v4', '1' );
 		}
 
+		// One-time migration (v0.16.0): editorial pivot. The comic Style Suffix
+		// is replaced by the editorial Style Template. Mirror the old suffix
+		// value into a deprecated-keyed option for one version cycle (so a
+		// customised value is recoverable / auditable) and seed the new
+		// template with its editorial default. The old option is intentionally
+		// NOT deleted this cycle. See docs/proposals/2026-05-29-image-pipeline-in-plugin-brief.md §8 Commit 1.
+		if ( ! get_option( 'prautoblogger_migrated_style_template_v0160' ) ) {
+			$old_suffix = get_option( 'prautoblogger_image_style_suffix', '' );
+			if ( '' !== $old_suffix && false === get_option( 'prautoblogger_image_style_suffix_deprecated', false ) ) {
+				update_option( 'prautoblogger_image_style_suffix_deprecated', $old_suffix );
+			}
+			// Only seed the new template if the admin has not already set one.
+			if ( '' === (string) get_option( 'prautoblogger_image_style_template', '' ) ) {
+				update_option( 'prautoblogger_image_style_template', PRAUTOBLOGGER_DEFAULT_IMAGE_STYLE_TEMPLATE );
+			}
+			update_option( 'prautoblogger_migrated_style_template_v0160', '1' );
+		}
+
 		// v0.9.0 — Runware as default image model. v0.10.0 — remove CF Workers AI.
 		PRAutoBlogger_Activator::migrate_default_image_v090();
 		PRAutoBlogger_Migrate_Remove_Cloudflare_V0100::run();

includes/core/class-image-attacher.php

@@ -0,0 +1,169 @@
+<?php
+declare(strict_types=1);
+
+/**
+ * phpcs:ignore WordPress.Files.FileName.InvalidClassFileName -- class naming convention differs from WordPress standard
+ *
+ * Persists generated images and composed variants for a post.
+ *
+ * Owns the media-library side of the image pipeline: sideloading the primary
+ * (featured) image with cost logging, sideloading composed OG/square variants
+ * with role/base meta-linking (no cost-tracker entries — composition is $0
+ * local CPU), and prepending the editable HTML caption to the post. Extracted
+ * from PRAutoBlogger_Image_Pipeline in v0.17.0 for 300-line compliance.
+ *
+ * Triggered by: PRAutoBlogger_Image_Pipeline during content generation run.
+ * Dependencies: PRAutoBlogger_Image_Media_Sideloader, PRAutoBlogger_Cost_Tracker,
+ *               PRAutoBlogger_Logger.
+ *
+ * @see core/class-image-pipeline.php         — Sole caller.
+ * @see core/class-image-composer.php         — Produces the variants this persists.
+ * @see core/class-image-media-sideloader.php — Media library import.
+ */
+class PRAutoBlogger_Image_Attacher {
+
+	/** Post meta key per composed variant role. */
+	private const ROLE_POST_META = array(
+		'og'     => '_prautoblogger_og_image_id',
+		'square' => '_prautoblogger_square_image_id',
+	);
+
+	/** @var PRAutoBlogger_Image_Media_Sideloader Imports bytes into the media library. */
+	private PRAutoBlogger_Image_Media_Sideloader $sideloader;
+
+	/** @var PRAutoBlogger_Cost_Tracker Logs primary image generation spend. */
+	private PRAutoBlogger_Cost_Tracker $cost_tracker;
+
+	/**
+	 * Construct with the pipeline's sideloader + cost tracker.
+	 *
+	 * @param PRAutoBlogger_Image_Media_Sideloader $sideloader   Media importer.
+	 * @param PRAutoBlogger_Cost_Tracker           $cost_tracker Spend logger.
+	 */
+	public function __construct( PRAutoBlogger_Image_Media_Sideloader $sideloader, PRAutoBlogger_Cost_Tracker $cost_tracker ) {
+		$this->sideloader   = $sideloader;
+		$this->cost_tracker = $cost_tracker;
+	}
+
+	/**
+	 * Sideload a primary image into the media library and log its cost.
+	 *
+	 * Side effects: media import, cost-tracker row, info log.
+	 *
+	 * @param array  $image_data Provider result with bytes, model, cost_usd.
+	 * @param int    $post_id    Post ID.
+	 * @param string $slot       Cost-tracking slot ('image_a' or 'image_b').
+	 * @param string $label      Human-readable label for logs.
+	 * @param string $alt_text   Alt text — the editorial caption (v0.17.0 bug
+	 *                           fix: previously the model name leaked here).
+	 *
+	 * @return int|\WP_Error Attachment ID on success.
+	 */
+	public function sideload_and_log( array $image_data, int $post_id, string $slot, string $label, string $alt_text = '' ) {
+		$attachment_id = $this->sideloader->sideload_image( $image_data, $post_id, $alt_text );
+
+		if ( is_wp_error( $attachment_id ) ) {
+			return $attachment_id;
+		}
+
+		$this->cost_tracker->log_image_generation(
+			$image_data['cost_usd'],
+			$image_data['model'] ?? 'unknown',
+			$post_id,
+			$slot
+		);
+
+		PRAutoBlogger_Logger::instance()->info(
+			sprintf( '%s for post %d (att %d, $%.4f)', $label, $post_id, $attachment_id, $image_data['cost_usd'] ),
+			'image_pipeline'
+		);
+
+		return $attachment_id;
+	}
+
+	/**
+	 * Sideload composed variants and meta-link them to post + base image.
+	 *
+	 * Each variant attachment gets `_prautoblogger_image_role` and
+	 * `_prautoblogger_base_attachment_id`; the post gets the role-specific
+	 * ID meta (see ROLE_POST_META). No cost-tracker entries — composition is
+	 * a $0 local stage. A failed variant sideload logs a WARNING and is
+	 * skipped; it never blocks the publish.
+	 *
+	 * @param array  $variants           Composed variants (role 'og'/'square' only are persisted).
+	 * @param int    $post_id            Post ID.
+	 * @param int    $base_attachment_id Featured attachment the variants derive from.
+	 * @param string $caption            Editorial caption (used as variant alt text).
+	 * @param string $model              Generation model recorded on the variant attachment.
+	 */
+	public function attach_variants( array $variants, int $post_id, int $base_attachment_id, string $caption, string $model ): void {
+		foreach ( $variants as $variant ) {
+			$role = (string) ( $variant['role'] ?? '' );
+			if ( ! isset( self::ROLE_POST_META[ $role ] ) ) {
+				continue;
+			}
+
+			$attachment_id = $this->sideloader->sideload_image(
+				array(
+					'bytes'      => (string) ( $variant['bytes'] ?? '' ),
+					'mime_type'  => (string) ( $variant['mime_type'] ?? 'image/png' ),
+					'width'      => (int) ( $variant['width'] ?? 0 ),
+					'height'     => (int) ( $variant['height'] ?? 0 ),
+					'model'      => $model,
+					'cost_usd'   => 0.0,
+					'latency_ms' => 0,
+				),
+				$post_id,
+				$caption,
+				$role
+			);
+
+			if ( is_wp_error( $attachment_id ) ) {
+				PRAutoBlogger_Logger::instance()->warning(
+					sprintf( 'Failed to sideload %s variant for post %d: %s', $role, $post_id, $attachment_id->get_error_message() ),
+					'image_composer'
+				);
+				continue;
+			}
+
+			update_post_meta( $attachment_id, '_prautoblogger_image_role', $role );
+			update_post_meta( $attachment_id, '_prautoblogger_base_attachment_id', $base_attachment_id );
+			update_post_meta( $post_id, self::ROLE_POST_META[ $role ], $attachment_id );
+
+			PRAutoBlogger_Logger::instance()->info(
+				sprintf( '%s variant for post %d (att %d, %dx%d)', $role, $post_id, $attachment_id, (int) $variant['width'], (int) $variant['height'] ),
+				'image_composer'
+			);
+		}
+	}
+
+	/**
+	 * Prepend the editorial caption as styled text at the top of the post.
+	 *
+	 * Only inserts the caption — NOT the image. The theme already displays
+	 * the featured image, so embedding it again would cause a duplicate.
+	 *
+	 * @param int    $post_id       Post ID.
+	 * @param int    $attachment_id Featured image attachment ID (unused; kept for parity with meta storage).
+	 * @param string $caption       Caption text shown below the image.
+	 */
+	public function prepend_caption_to_post( int $post_id, int $attachment_id, string $caption ): void {
+		$post = get_post( $post_id );
+		if ( ! $post ) {
+			return;
+		}
+
+		// Caption-only block — the theme handles the featured image display.
+		$caption_html = sprintf(
+			'<p class="prautoblogger-comic-caption" style="text-align:center;font-style:italic;color:#555;font-size:1.1em;margin:0 0 2em 0;">— "%s"</p>',
+			esc_html( $caption )
+		);
+
+		wp_update_post(
+			array(
+				'ID'           => $post_id,
+				'post_content' => $caption_html . "\n\n" . $post->post_content,
+			)
+		);
+	}
+}

includes/core/class-image-composer-canvas.php

@@ -0,0 +1,186 @@
+<?php
+declare(strict_types=1);
+
+/**
+ * phpcs:ignore WordPress.Files.FileName.InvalidClassFileName -- class naming convention differs from WordPress standard
+ *
+ * Low-level Imagick canvas primitives for the deterministic image composer.
+ *
+ * Capability smoke test, base-image loading, cover-cropping, logo placement,
+ * and deterministic PNG encoding. No WordPress functions anywhere in this
+ * class — it runs unchanged inside the standalone render harness used to
+ * produce the PR sample images.
+ *
+ * Triggered by: PRAutoBlogger_Image_Composer_Imagick (renderer) per variant.
+ * Dependencies: ext-imagick (callers must gate on is_imagick_usable()).
+ *
+ * @see core/class-image-composer-imagick.php — Sole consumer.
+ * @see core/class-image-composer.php         — Caches the capability probe result.
+ */
+class PRAutoBlogger_Image_Composer_Canvas {
+
+	/**
+	 * Probe whether Imagick can do everything the renderer needs: PNG
+	 * encode plus TTF text annotation (the smoke test draws one glyph on a
+	 * tiny in-memory canvas). Cheap to run but callers should cache it.
+	 *
+	 * Side effects: none beyond a transient in-memory Imagick object.
+	 *
+	 * @param string $font_path Absolute path to a bundled TTF used for the smoke test.
+	 *
+	 * @return bool True when full compositing is available.
+	 */
+	public static function is_imagick_usable( string $font_path ): bool {
+		if ( ! extension_loaded( 'imagick' ) || ! class_exists( '\Imagick' ) ) {
+			return false;
+		}
+
+		try {
+			$formats = \Imagick::queryFormats( 'PNG' );
+			if ( empty( $formats ) ) {
+				return false;
+			}
+
+			if ( ! is_readable( $font_path ) ) {
+				return false;
+			}
+
+			$probe = new \Imagick();
+			$probe->newImage( 8, 8, new \ImagickPixel( '#ffffff' ), 'png' );
+			$draw = new \ImagickDraw();
+			$draw->setFont( $font_path );
+			$draw->setFontSize( 6 );
+			$probe->annotateImage( $draw, 1, 6, 0.0, 'P' );
+			$probe->clear();
+
+			return true;
+		} catch ( \Throwable $e ) {
+			return false;
+		}
+	}
+
+	/**
+	 * Load base image bytes into an Imagick object (first frame only).
+	 *
+	 * @param string $bytes Raw image bytes (PNG/JPEG/WebP — any readable format).
+	 *
+	 * @return \Imagick Loaded image.
+	 * @throws \RuntimeException When the bytes cannot be decoded.
+	 */
+	public static function load_base( string $bytes ): \Imagick {
+		$image = new \Imagick();
+		if ( ! $image->readImageBlob( $bytes ) ) {
+			throw new \RuntimeException( 'Composer could not decode base image bytes.' );
+		}
+		$image->setIteratorIndex( 0 );
+		$image = $image->coalesceImages()->current();
+		$image->setImagePage( 0, 0, 0, 0 );
+
+		return $image;
+	}
+
+	/**
+	 * Center cover-crop an image to exact target dimensions without upscaling.
+	 *
+	 * Crops the largest centered region matching the target aspect ratio,
+	 * then scales DOWN to the target. Refuses (returns false) when the source
+	 * is too small to fill the target without upscaling.
+	 *
+	 * Side effects: mutates $image in place on success.
+	 *
+	 * @param \Imagick $image  Source image (mutated).
+	 * @param int      $target_w Target width in px.
+	 * @param int      $target_h Target height in px.
+	 *
+	 * @return bool False when the crop would require upscaling.
+	 */
+	public static function cover_crop( \Imagick $image, int $target_w, int $target_h ): bool {
+		$width  = $image->getImageWidth();
+		$height = $image->getImageHeight();
+		if ( $width < 1 || $height < 1 ) {
+			return false;
+		}
+
+		$ratio = max( $target_w / $width, $target_h / $height );
+		if ( $ratio > 1.0 ) {
+			return false;
+		}
+
+		$src_w = min( $width, (int) round( $target_w / $ratio ) );
+		$src_h = min( $height, (int) round( $target_h / $ratio ) );
+		$x     = (int) floor( ( $width - $src_w ) / 2 );
+		$y     = (int) floor( ( $height - $src_h ) / 2 );
+
+		$image->cropImage( $src_w, $src_h, $x, $y );
+		$image->setImagePage( 0, 0, 0, 0 );
+		$image->resizeImage( $target_w, $target_h, \Imagick::FILTER_LANCZOS, 1 );
+
+		return true;
+	}
+
+	/**
+	 * Composite a brand PNG onto the canvas at a target height and opacity.
+	 *
+	 * @param \Imagick $canvas     Destination canvas (mutated).
+	 * @param string   $asset_path Absolute path to the brand PNG.
+	 * @param int      $target_h   Logo height in px (width keeps aspect).
+	 * @param int      $x          Left position on the canvas.
+	 * @param int      $y          Top position on the canvas.
+	 * @param float    $opacity    1.0 = opaque, 0.55 = subtle corner mark.
+	 *
+	 * @return int Rendered logo width in px (useful for caption x-offsets).
+	 * @throws \RuntimeException When the asset is missing or unreadable.
+	 */
+	public static function place_logo( \Imagick $canvas, string $asset_path, int $target_h, int $x, int $y, float $opacity = 1.0 ): int {
+		if ( ! is_readable( $asset_path ) ) {
+			throw new \RuntimeException( 'Composer brand asset missing: ' . basename( $asset_path ) );
+		}
+
+		$logo = new \Imagick( $asset_path );
+		$logo->setImagePage( 0, 0, 0, 0 );
+		$scale    = $target_h / max( 1, $logo->getImageHeight() );
+		$target_w = max( 1, (int) round( $logo->getImageWidth() * $scale ) );
+		$logo->resizeImage( $target_w, $target_h, \Imagick::FILTER_LANCZOS, 1 );
+
+		if ( $opacity < 1.0 ) {
+			$logo->evaluateImage( \Imagick::EVALUATE_MULTIPLY, max( 0.0, $opacity ), \Imagick::CHANNEL_ALPHA );
+		}
+
+		$canvas->compositeImage( $logo, \Imagick::COMPOSITE_OVER, $x, $y );
+		$logo->clear();
+
+		return $target_w;
+	}
+
+	/**
+	 * Encode a canvas as a deterministic PNG variant payload.
+	 *
+	 * Strips all metadata and excludes PNG date/time chunks so identical
+	 * inputs produce byte-identical output in the same environment.
+	 *
+	 * Side effects: destroys the Imagick object after encoding.
+	 *
+	 * @param \Imagick $image Finished canvas.
+	 * @param string   $role  Variant role: 'featured', 'og', or 'square'.
+	 *
+	 * @return array{bytes: string, mime_type: string, width: int, height: int, role: string}
+	 */
+	public static function finalize_png( \Imagick $image, string $role ): array {
+		$image->setImageFormat( 'png' );
+		$image->setImageDepth( 8 );
+		$image->stripImage();
+		$image->setOption( 'png:exclude-chunks', 'date,time' );
+		$image->setOption( 'png:compression-level', '9' );
+
+		$variant = array(
+			'bytes'     => $image->getImageBlob(),
+			'mime_type' => 'image/png',
+			'width'     => $image->getImageWidth(),
+			'height'    => $image->getImageHeight(),
+			'role'      => $role,
+		);
+		$image->clear();
+
+		return $variant;
+	}
+}

includes/core/class-image-composer-editor.php

@@ -0,0 +1,114 @@
+<?php
+declare(strict_types=1);
+
+/**
+ * phpcs:ignore WordPress.Files.FileName.InvalidClassFileName -- class naming convention differs from WordPress standard
+ *
+ * Resize-only composer rung backed by wp_get_image_editor() (GD path).
+ *
+ * Used when Imagick is unusable: emits unbranded, caption-free center-crops
+ * at each variant's exact dimensions. Variants that would require upscaling
+ * (e.g. a 1080×1080 square from a 1200×632 base — WP's editor never upscales
+ * on crop-resize) are skipped; the OG crop is always achievable from the
+ * standard base. Output is GD PNG, which embeds no timestamps, so this rung
+ * is deterministic too.
+ *
+ * Triggered by: PRAutoBlogger_Image_Composer when the capability probe says 'gd'.
+ * Dependencies: wp_get_image_editor(), get_temp_dir(), PRAutoBlogger_Logger.
+ *
+ * @see core/class-image-composer.php — Orchestrator + degradation ladder.
+ * @see core/class-image-composer-imagick.php — The full-fidelity rung this replaces.
+ */
+class PRAutoBlogger_Image_Composer_Editor {
+
+	/**
+	 * Render resize-only variants for the requested roles.
+	 *
+	 * Side effects: temp file write/delete per variant; debug log on skips.
+	 *
+	 * @param string                               $bytes  Base image bytes.
+	 * @param string[]                             $roles  Variant roles to attempt ('og', 'square').
+	 * @param array<string, array<string, mixed>>  $layout Layout geometry (for target dimensions).
+	 *
+	 * @return array<int, array{bytes: string, mime_type: string, width: int, height: int, role: string}>
+	 *               Successfully resized variants only (possibly empty).
+	 */
+	public function compose_variants( string $bytes, array $roles, array $layout ): array {
+		$variants = array();
+
+		foreach ( $roles as $role ) {
+			$target_w = (int) ( $layout[ $role ]['width'] ?? 0 );
+			$target_h = (int) ( $layout[ $role ]['height'] ?? 0 );
+			if ( $target_w < 1 || $target_h < 1 ) {
+				continue;
+			}
+
+			$resized = $this->cover_crop( $bytes, $target_w, $target_h );
+			if ( null === $resized ) {
+				PRAutoBlogger_Logger::instance()->debug(
+					sprintf( 'Resize-only %s variant skipped (editor failure or would upscale).', $role ),
+					'image_composer'
+				);
+				continue;
+			}
+
+			$resized['role'] = $role;
+			$variants[]      = $resized;
+		}
+
+		return $variants;
+	}
+
+	/**
+	 * Center-crop bytes to exact dimensions with the portable WP editor.
+	 *
+	 * @param string $bytes    Source image bytes.
+	 * @param int    $target_w Target width in px.
+	 * @param int    $target_h Target height in px.
+	 *
+	 * @return array{bytes: string, mime_type: string, width: int, height: int}|null
+	 *               Null when the editor fails or cannot hit the exact size
+	 *               without upscaling.
+	 */
+	private function cover_crop( string $bytes, int $target_w, int $target_h ): ?array {
+		$temp = get_temp_dir() . uniqid( 'prab_compose_', true ) . '.png';
+		// phpcs:ignore WordPress.WP.AlternativeFunctions.file_system_operations_file_put_contents -- temp file, same pattern as the sideloader.
+		if ( false === file_put_contents( $temp, $bytes ) ) {
+			return null;
+		}
+
+		try {
+			$editor = wp_get_image_editor( $temp );
+			if ( is_wp_error( $editor ) ) {
+				return null;
+			}
+			if ( is_wp_error( $editor->resize( $target_w, $target_h, true ) ) ) {
+				return null;
+			}
+
+			$size = $editor->get_size();
+			if ( (int) $size['width'] !== $target_w || (int) $size['height'] !== $target_h ) {
+				return null; // Exact size not reachable without upscaling.
+			}
+
+			if ( is_wp_error( $editor->save( $temp, 'image/png' ) ) ) {
+				return null;
+			}
+			// phpcs:ignore WordPress.WP.AlternativeFunctions.file_get_contents_file_get_contents -- temp file we just wrote.
+			$out = file_get_contents( $temp );
+
+			return false === $out ? null : array(
+				'bytes'     => $out,
+				'mime_type' => 'image/png',
+				'width'     => $target_w,
+				'height'    => $target_h,
+			);
+		} catch ( \Throwable $e ) {
+			PRAutoBlogger_Logger::instance()->debug( 'WP image editor crop threw: ' . $e->getMessage(), 'image_composer' );
+			return null;
+		} finally {
+			// phpcs:ignore WordPress.PHP.NoSilencedErrors.Discouraged -- best-effort temp cleanup.
+			@unlink( $temp );
+		}
+	}
+}

includes/core/class-image-composer-imagick.php

@@ -0,0 +1,250 @@
+<?php
+declare(strict_types=1);
+
+/**
+ * phpcs:ignore WordPress.Files.FileName.InvalidClassFileName -- class naming convention differs from WordPress standard
+ *
+ * Imagick renderer for the deterministic image composer (full-fidelity rung).
+ *
+ * Renders the three branded variants from one base image: corner-marked
+ * featured (1200×632), teal-band OG (1200×630), and card-layout square
+ * (1080×1080). No WordPress functions anywhere — layout geometry and asset
+ * directories arrive via the constructor, so the class runs unchanged inside
+ * the standalone render harness that produced the PR samples. Methods throw
+ * on failure; the orchestrator catches and degrades, so a renderer error can
+ * never fail a publish.
+ *
+ * Triggered by: PRAutoBlogger_Image_Composer when the capability probe says 'imagick'.
+ * Dependencies: ext-imagick, bundled brand PNGs + OFL fonts,
+ *               PRAutoBlogger_Image_Composer_Canvas (primitives),
+ *               PRAutoBlogger_Image_Composer_Layout (caption clamp).
+ *
+ * @see core/class-image-composer.php        — Orchestrator + degradation ladder.
+ * @see core/class-image-composer-canvas.php — Crop/logo/PNG primitives.
+ * @see core/class-image-composer-layout.php — Geometry defaults + clamp.
+ */
+class PRAutoBlogger_Image_Composer_Imagick {
+
+	/** @var array<string, array<string, mixed>> Layout geometry keyed by role. */
+	private array $layout;
+
+	/** @var string Absolute path to the vendored brand PNG directory (trailing slash). */
+	private string $brand_dir;
+
+	/** @var string Absolute path to the bundled font directory (trailing slash). */
+	private string $fonts_dir;
+
+	/**
+	 * Construct with resolved layout + asset locations.
+	 *
+	 * @param array<string, array<string, mixed>> $layout    Filtered layout (see Layout::defaults()).
+	 * @param string                              $brand_dir Brand PNG directory, trailing slash.
+	 * @param string                              $fonts_dir Font directory, trailing slash.
+	 */
+	public function __construct( array $layout, string $brand_dir, string $fonts_dir ) {
+		$this->layout    = $layout;
+		$this->brand_dir = $brand_dir;
+		$this->fonts_dir = $fonts_dir;
+	}
+
+	/**
+	 * Featured variant: base image untouched except a subtle corner mark.
+	 *
+	 * @param string $bytes Base image bytes.
+	 *
+	 * @return array{bytes: string, mime_type: string, width: int, height: int, role: string}
+	 * @throws \RuntimeException|\ImagickException On decode/asset failure.
+	 */
+	public function compose_featured( string $bytes ): array {
+		$conf   = $this->layout['featured'];
+		$canvas = PRAutoBlogger_Image_Composer_Canvas::load_base( $bytes );
+
+		$mark_h = (int) $conf['mark_height'];
+		$inset  = (int) $conf['mark_inset'];
+		// The mark asset is square, so rendered width equals the height.
+		PRAutoBlogger_Image_Composer_Canvas::place_logo(
+			$canvas,
+			$this->brand_dir . $conf['mark_asset'],
+			$mark_h,
+			$canvas->getImageWidth() - $mark_h - $inset,
+			$canvas->getImageHeight() - $mark_h - $inset,
+			(float) $conf['mark_opacity']
+		);
+
+		return PRAutoBlogger_Image_Composer_Canvas::finalize_png( $canvas, 'featured' );
+	}
+
+	/**
+	 * OG variant (1200×630): center-cropped base, bottom teal band with the
+	 * brand mark and the clamped caption in white.
+	 *
+	 * @param string $bytes   Base image bytes.
+	 * @param string $caption Editorial caption (clamped to 2 lines).
+	 *
+	 * @return array{bytes: string, mime_type: string, width: int, height: int, role: string}
+	 * @throws \RuntimeException|\ImagickException On decode/crop/asset failure.
+	 */
+	public function compose_og( string $bytes, string $caption ): array {
+		$conf   = $this->layout['og'];
+		$width  = (int) $conf['width'];
+		$height = (int) $conf['height'];
+		$band_h = (int) $conf['band_height'];
+		$band_y = $height - $band_h;
+
+		$canvas = PRAutoBlogger_Image_Composer_Canvas::load_base( $bytes );
+		if ( ! PRAutoBlogger_Image_Composer_Canvas::cover_crop( $canvas, $width, $height ) ) {
+			$canvas->clear();
+			throw new \RuntimeException( 'OG variant would require upscaling the base image.' );
+		}
+
+		$this->draw_rect( $canvas, 0, $band_y, $width, $height, (string) $conf['band_color'] );
+
+		$logo_h = (int) $conf['logo_height'];
+		$logo_w = PRAutoBlogger_Image_Composer_Canvas::place_logo(
+			$canvas,
+			$this->brand_dir . $conf['logo_asset'],
+			$logo_h,
+			(int) $conf['logo_x'],
+			$band_y + (int) floor( ( $band_h - $logo_h ) / 2 )
+		);
+
+		$lines = PRAutoBlogger_Image_Composer_Layout::clamp_caption(
+			$caption,
+			(int) $conf['caption_chars_per_line'],
+			(int) $conf['caption_max_lines']
+		);
+		$this->draw_lines(
+			$canvas,
+			$lines,
+			array(
+				'font'        => $this->fonts_dir . $conf['caption_font'],
+				'size'        => (float) $conf['caption_size'],
+				'color'       => (string) $conf['caption_color'],
+				'line_height' => (float) $conf['caption_line_height'],
+				'x'           => (int) $conf['logo_x'] + $logo_w + (int) $conf['caption_gap'],
+				'center_y'    => $band_y + (int) floor( $band_h / 2 ),
+				'align'       => \Imagick::ALIGN_LEFT,
+			)
+		);
+
+		return PRAutoBlogger_Image_Composer_Canvas::finalize_png( $canvas, 'og' );
+	}
+
+	/**
+	 * Square variant (1080×1080, card layout, no upscaling): full base
+	 * downscaled into the top slice, cream caption panel in Poppins Bold,
+	 * teal footer band with the horizontal reverse lockup.
+	 *
+	 * @param string $bytes   Base image bytes.
+	 * @param string $caption Editorial caption (clamped to 3 lines).
+	 *
+	 * @return array{bytes: string, mime_type: string, width: int, height: int, role: string}
+	 * @throws \RuntimeException|\ImagickException On decode/crop/asset failure.
+	 */
+	public function compose_square( string $bytes, string $caption ): array {
+		$conf     = $this->layout['square'];
+		$width    = (int) $conf['width'];
+		$height   = (int) $conf['height'];
+		$slice_h  = (int) $conf['slice_height'];
+		$footer_h = (int) $conf['footer_height'];
+		$footer_y = $height - $footer_h;
+
+		$slice = PRAutoBlogger_Image_Composer_Canvas::load_base( $bytes );
+		if ( ! PRAutoBlogger_Image_Composer_Canvas::cover_crop( $slice, $width, $slice_h ) ) {
+			$slice->clear();
+			throw new \RuntimeException( 'Square variant would require upscaling the base image.' );
+		}
+
+		$canvas = new \Imagick();
+		$canvas->newImage( $width, $height, new \ImagickPixel( (string) $conf['panel_color'] ), 'png' );
+		$canvas->compositeImage( $slice, \Imagick::COMPOSITE_OVER, 0, 0 );
+		$slice->clear();
+
+		$this->draw_rect( $canvas, 0, $footer_y, $width, $height, (string) $conf['footer_color'] );
+
+		$logo_h = (int) $conf['footer_logo_height'];
+		$logo   = new \Imagick( $this->brand_dir . $conf['footer_logo_asset'] );
+		$logo_w = (int) round( $logo->getImageWidth() * ( $logo_h / max( 1, $logo->getImageHeight() ) ) );
+		$logo->clear();
+		PRAutoBlogger_Image_Composer_Canvas::place_logo(
+			$canvas,
+			$this->brand_dir . $conf['footer_logo_asset'],
+			$logo_h,
+			(int) floor( ( $width - $logo_w ) / 2 ),
+			$footer_y + (int) floor( ( $footer_h - $logo_h ) / 2 )
+		);
+
+		$lines = PRAutoBlogger_Image_Composer_Layout::clamp_caption(
+			$caption,
+			(int) $conf['caption_chars_per_line'],
+			(int) $conf['caption_max_lines']
+		);
+		$this->draw_lines(
+			$canvas,
+			$lines,
+			array(
+				'font'        => $this->fonts_dir . $conf['caption_font'],
+				'size'        => (float) $conf['caption_size'],
+				'color'       => (string) $conf['caption_color'],
+				'line_height' => (float) $conf['caption_line_height'],
+				'x'           => (int) floor( $width / 2 ),
+				'center_y'    => $slice_h + (int) floor( ( $footer_y - $slice_h ) / 2 ),
+				'align'       => \Imagick::ALIGN_CENTER,
+			)
+		);
+
+		return PRAutoBlogger_Image_Composer_Canvas::finalize_png( $canvas, 'square' );
+	}
+
+	/**
+	 * Fill an axis-aligned rectangle on the canvas.
+	 *
+	 * @param \Imagick $canvas Destination canvas (mutated).
+	 * @param int      $x1     Left.
+	 * @param int      $y1     Top.
+	 * @param int      $x2     Right.
+	 * @param int      $y2     Bottom.
+	 * @param string   $color  Hex fill color.
+	 */
+	private function draw_rect( \Imagick $canvas, int $x1, int $y1, int $x2, int $y2, string $color ): void {
+		$draw = new \ImagickDraw();
+		$draw->setFillColor( new \ImagickPixel( $color ) );
+		$draw->rectangle( (float) $x1, (float) $y1, (float) $x2, (float) $y2 );
+		$canvas->drawImage( $draw );
+	}
+
+	/**
+	 * Draw pre-clamped caption lines vertically centered around center_y.
+	 *
+	 * @param \Imagick $canvas Destination canvas (mutated).
+	 * @param string[] $lines  Already-clamped lines (may be empty — no-op).
+	 * @param array{font: string, size: float, color: string, line_height: float, x: int, center_y: int, align: int} $opts Text options.
+	 *
+	 * @throws \RuntimeException When the bundled font file is missing.
+	 */
+	private function draw_lines( \Imagick $canvas, array $lines, array $opts ): void {
+		if ( empty( $lines ) ) {
+			return;
+		}
+		if ( ! is_readable( $opts['font'] ) ) {
+			throw new \RuntimeException( 'Composer font missing: ' . basename( $opts['font'] ) );
+		}
+
+		$draw = new \ImagickDraw();
+		$draw->setFont( $opts['font'] );
+		$draw->setFontSize( $opts['size'] );
+		$draw->setFillColor( new \ImagickPixel( $opts['color'] ) );
+		$draw->setTextAlignment( $opts['align'] );
+		$draw->setTextAntialias( true );
+
+		$metrics     = $canvas->queryFontMetrics( $draw, 'Hg' );
+		$line_step   = (int) round( $opts['size'] * $opts['line_height'] );
+		$block_h     = ( count( $lines ) - 1 ) * $line_step + (int) round( $metrics['ascender'] - $metrics['descender'] );
+		$baseline    = $opts['center_y'] - (int) floor( $block_h / 2 ) + (int) round( $metrics['ascender'] );
+
+		foreach ( $lines as $line ) {
+			$canvas->annotateImage( $draw, (float) $opts['x'], (float) $baseline, 0.0, $line );
+			$baseline += $line_step;
+		}
+	}
+}

includes/core/class-image-composer-layout.php

@@ -0,0 +1,173 @@
+<?php
+declare(strict_types=1);
+
+/**
+ * phpcs:ignore WordPress.Files.FileName.InvalidClassFileName -- class naming convention differs from WordPress standard
+ *
+ * Geometry defaults and caption clamping for the deterministic image composer.
+ *
+ * Pure functions and constants only — no WordPress, no Imagick. This keeps
+ * the class unit-testable and usable from a standalone render harness. The
+ * orchestrator exposes defaults() through the `prautoblogger_image_compose_layout`
+ * filter; geometry is intentionally NOT a settings-page surface (promote to
+ * settings only if the CEO asks to tune it — see ARCHITECTURE.md #21).
+ *
+ * Triggered by: PRAutoBlogger_Image_Composer (orchestrator) at compose time.
+ * Dependencies: mbstring (bundled with WordPress via compat polyfills).
+ *
+ * @see core/class-image-composer.php          — Applies the layout filter.
+ * @see core/class-image-composer-imagick.php  — Consumes the geometry values.
+ * @see tests/unit/Core/ImageComposerLayoutTest.php — Clamp boundary cases.
+ */
+class PRAutoBlogger_Image_Composer_Layout {
+
+	/** Brand tokens (locked — see peptide-repo-brand README). */
+	public const COLOR_TEAL   = '#1B8A92';
+	public const COLOR_LIME   = '#7FD600';
+	public const COLOR_ORANGE = '#FF8A3D';
+	public const COLOR_INK    = '#0D0D0D';
+	public const COLOR_CREAM  = '#FAFAF7';
+
+	/** Ellipsis appended when a caption overflows its line budget. */
+	public const ELLIPSIS = '…';
+
+	/**
+	 * Default geometry for every composed variant.
+	 *
+	 * Asset filenames resolve against assets/brand/ and assets/fonts/ in the
+	 * plugin; sizes are px. Values were tuned against rendered samples (see
+	 * PR #thread 2026-06-image-composer assets).
+	 *
+	 * @return array<string, array<string, mixed>> Keyed by role: featured, og, square.
+	 */
+	public static function defaults(): array {
+		return array(
+			'featured' => array(
+				'mark_asset'   => 'logo-mark-small-56.png',
+				'mark_height'  => 28,
+				'mark_inset'   => 16,
+				'mark_opacity' => 0.55,
+			),
+			'og'       => array(
+				'width'                 => 1200,
+				'height'                => 630,
+				'band_height'           => 120,
+				'band_color'            => self::COLOR_TEAL,
+				'logo_asset'            => 'logo-mark-small-112.png',
+				'logo_height'           => 64,
+				'logo_x'                => 40,
+				'caption_font'          => 'Poppins-SemiBold.ttf',
+				'caption_size'          => 32,
+				'caption_color'         => '#FFFFFF',
+				'caption_gap'           => 24,
+				'caption_margin_right'  => 40,
+				'caption_max_lines'     => 2,
+				'caption_chars_per_line' => 52,
+				'caption_line_height'   => 1.3,
+			),
+			'square'   => array(
+				'width'                 => 1080,
+				'height'                => 1080,
+				'slice_height'          => 569,
+				'panel_color'           => self::COLOR_CREAM,
+				'footer_height'         => 96,
+				'footer_color'          => self::COLOR_TEAL,
+				'footer_logo_asset'     => 'logo-horizontal-reverse-128.png',
+				'footer_logo_height'    => 48,
+				'caption_font'          => 'Poppins-Bold.ttf',
+				'caption_size'          => 48,
+				'caption_color'         => self::COLOR_INK,
+				'caption_max_lines'     => 3,
+				'caption_chars_per_line' => 36,
+				'caption_side_padding'  => 64,
+				'caption_line_height'   => 1.3,
+			),
+		);
+	}
+
+	/**
+	 * Clamp and word-wrap a caption to a hard per-variant budget.
+	 *
+	 * Whitespace is collapsed, words wrap at word boundaries, words longer
+	 * than a full line are hard-split, and overflow beyond max_lines is cut
+	 * with a trailing ellipsis. Multibyte-safe (mb_* functions).
+	 *
+	 * Side effects: none (pure).
+	 *
+	 * @param string $caption        Raw caption text (any length, any script).
+	 * @param int    $chars_per_line Hard character budget per line (min 1).
+	 * @param int    $max_lines      Maximum number of lines (min 1).
+	 *
+	 * @return string[] Wrapped lines; empty array when the caption is blank.
+	 */
+	public static function clamp_caption( string $caption, int $chars_per_line, int $max_lines ): array {
+		$chars_per_line = max( 1, $chars_per_line );
+		$max_lines      = max( 1, $max_lines );
+		$normalized     = trim( (string) preg_replace( '/\s+/u', ' ', $caption ) );
+
+		if ( '' === $normalized ) {
+			return array();
+		}
+
+		$lines = array();
+		$line  = '';
+
+		foreach ( explode( ' ', $normalized ) as $word ) {
+			// Hard-split words longer than a full line so they cannot overflow.
+			while ( mb_strlen( $word ) > $chars_per_line ) {
+				if ( '' !== $line ) {
+					$lines[] = $line;
+					$line    = '';
+					if ( count( $lines ) >= $max_lines ) {
+						return self::ellipsize( $lines, $chars_per_line );
+					}
+				}
+				$lines[] = mb_substr( $word, 0, $chars_per_line );
+				$word    = mb_substr( $word, $chars_per_line );
+				if ( count( $lines ) >= $max_lines ) {
+					return self::ellipsize( $lines, $chars_per_line );
+				}
+			}
+
+			$candidate = ( '' === $line ) ? $word : $line . ' ' . $word;
+			if ( mb_strlen( $candidate ) <= $chars_per_line ) {
+				$line = $candidate;
+				continue;
+			}
+
+			$lines[] = $line;
+			$line    = $word;
+			if ( count( $lines ) >= $max_lines ) {
+				return self::ellipsize( $lines, $chars_per_line );
+			}
+		}
+
+		if ( '' !== $line ) {
+			$lines[] = $line;
+		}
+
+		return $lines;
+	}
+
+	/**
+	 * Append an ellipsis to the final line, trimming first if the line is
+	 * already at the character budget so the result never exceeds it.
+	 *
+	 * @param string[] $lines          Lines already at the max-line count.
+	 * @param int      $chars_per_line Hard character budget per line.
+	 *
+	 * @return string[] Lines with a trailing ellipsis on the last one.
+	 */
+	private static function ellipsize( array $lines, int $chars_per_line ): array {
+		$last_index = count( $lines ) - 1;
+		$last       = $lines[ $last_index ];
+
+		if ( mb_strlen( $last ) + 1 > $chars_per_line ) {
+			$last = rtrim( mb_substr( $last, 0, max( 0, $chars_per_line - 1 ) ) );
+		}
+
+		$lines[ $last_index ] = $last . self::ELLIPSIS;
+
+		return $lines;
+	}
+}

includes/core/class-image-composer.php

@@ -0,0 +1,298 @@
+<?php
+declare(strict_types=1);
+
+/**
+ * phpcs:ignore WordPress.Files.FileName.InvalidClassFileName -- class naming convention differs from WordPress standard
+ *
+ * Orchestrates deterministic image composition with a capability ladder.
+ *
+ * Sits between the provider's raw bytes and the media sideloader. Probes the
+ * environment once (cached in an option keyed by a PHP/extension fingerprint,
+ * so it auto-invalidates when the host changes — Hostinger extension state
+ * has flipped before), then renders per the ladder: (1) Imagick usable →
+ * full branded compositing; (2) GD via WP editor → resize-only variants, no
+ * branding/text, WARNING once; (3) no image library → pass-through, WARNING
+ * once. compose() never throws and always returns a featured-first non-empty
+ * list, so a composition failure can never block a publish. Local CPU only:
+ * $0, no provider call; duration is logged on the image_composer channel.
+ *
+ * Triggered by: PRAutoBlogger_Image_Pipeline after batch results + NSFW retry,
+ *               before sideloading.
+ * Dependencies: Image_Composer_Imagick (rung 1), Image_Composer_Editor (rung 2),
+ *               Image_Composer_Canvas (probe), Image_Composer_Layout, Logger.
+ *
+ * @see core/interface-image-composer.php — The contract.
+ * @see core/class-image-pipeline.php     — Caller.
+ * @see core/class-image-attacher.php     — Persists returned variants.
+ * @see ARCHITECTURE.md                   — Decision #21.
+ */
+class PRAutoBlogger_Image_Composer implements PRAutoBlogger_Image_Composer_Interface {
+
+	/** Option keys (prautoblogger_ prefix keeps the uninstall sweep effective). */
+	public const OPTION_ENABLED      = 'prautoblogger_image_compose_enabled';
+	public const OPTION_VARIANTS     = 'prautoblogger_image_compose_variants';
+	public const OPTION_MARK_ENABLED = 'prautoblogger_image_featured_mark_enabled';
+	public const OPTION_CAPABILITY   = 'prautoblogger_image_compose_capability';
+
+	/** Capability rungs. */
+	public const CAP_IMAGICK = 'imagick';
+	public const CAP_GD      = 'gd';
+	public const CAP_NONE    = 'none';
+
+	/** @var PRAutoBlogger_Image_Composer_Imagick|null Lazily built; injectable for tests. */
+	private ?PRAutoBlogger_Image_Composer_Imagick $renderer;
+
+	/** @var bool Degradation WARNING fired this run (once per PHP process). */
+	private static bool $warned_this_run = false;
+
+	/**
+	 * Construct, optionally injecting a renderer (tests).
+	 * @param PRAutoBlogger_Image_Composer_Imagick|null $renderer Optional renderer override.
+	 */
+	public function __construct( ?PRAutoBlogger_Image_Composer_Imagick $renderer = null ) {
+		$this->renderer = $renderer;
+	}
+
+	/**
+	 * Compose final variants for one generated image. See the interface for
+	 * the full contract; this implementation never throws.
+	 * Side effects: reads options, may cache the capability probe, logs.
+	 *
+	 * @param array $image_data Provider result (bytes, mime_type, width, height, ...).
+	 * @param array $context    {post_id, caption, title, slot}.
+	 * @return array<int, array{bytes: string, mime_type: string, width: int, height: int, role: string}>
+	 */
+	public function compose( array $image_data, array $context ): array {
+		$passthrough = array( $this->passthrough_variant( $image_data ) );
+
+		if ( '' === $passthrough[0]['bytes'] || '1' !== (string) get_option( self::OPTION_ENABLED, '1' ) ) {
+			return $passthrough;
+		}
+
+		$started    = microtime( true );
+		$bytes      = $passthrough[0]['bytes'];
+		$capability = $this->resolve_capability();
+		$caption    = (string) ( $context['caption'] ?? '' );
+		$roles      = ( 'image_a' === (string) ( $context['slot'] ?? 'image_a' ) )
+			? $this->configured_variants()
+			: array();
+
+		if ( self::CAP_IMAGICK === $capability ) {
+			$variants = $this->compose_via_imagick( $bytes, $caption, $roles, $passthrough[0] );
+		} elseif ( self::CAP_GD === $capability ) {
+			$this->warn_once( 'Imagick unavailable — emitting resize-only variants without branding or caption.' );
+			$editor   = new PRAutoBlogger_Image_Composer_Editor();
+			$variants = array_merge( $passthrough, $editor->compose_variants( $bytes, $roles, $this->layout() ) );
+		} else {
+			$this->warn_once( 'No usable image library — base image passed through unbranded.' );
+			$variants = $passthrough;
+		}
+
+		PRAutoBlogger_Logger::instance()->info(
+			sprintf(
+				'Composed %d variant(s) for post %d in %dms ($0, local, capability: %s).',
+				count( $variants ),
+				(int) ( $context['post_id'] ?? 0 ),
+				(int) round( ( microtime( true ) - $started ) * 1000 ),
+				$capability
+			),
+			'image_composer'
+		);
+
+		return $variants;
+	}
+
+	/**
+	 * Full compositing rung. Each render is individually guarded: a featured
+	 * failure degrades to pass-through, a variant failure skips that variant.
+	 *
+	 * @param string $bytes       Base image bytes.
+	 * @param string $caption     Editorial caption for OG/square.
+	 * @param array  $roles       Variant roles to render ('og', 'square').
+	 * @param array  $passthrough Pass-through featured variant (fallback).
+	 * @return array<int, array<string, mixed>> Featured-first variant list.
+	 */
+	private function compose_via_imagick( string $bytes, string $caption, array $roles, array $passthrough ): array {
+		$variants = array();
+
+		if ( '1' === (string) get_option( self::OPTION_MARK_ENABLED, '1' ) ) {
+			$featured   = $this->try_render( 'featured', $bytes, $caption );
+			$variants[] = null === $featured ? $passthrough : $featured;
+		} else {
+			$variants[] = $passthrough;
+		}
+
+		foreach ( $roles as $role ) {
+			$variant = $this->try_render( $role, $bytes, $caption );
+			if ( null !== $variant ) {
+				$variants[] = $variant;
+			}
+		}
+
+		return $variants;
+	}
+
+	/**
+	 * Render one role via the Imagick renderer. Any throwable or malformed
+	 * result (empty bytes) maps to one per-run WARNING + null (caller degrades).
+	 * @param string $role    'featured', 'og', or 'square'.
+	 * @param string $bytes   Base image bytes.
+	 * @param string $caption Editorial caption.
+	 * @return array<string, mixed>|null Variant payload or null on failure.
+	 */
+	private function try_render( string $role, string $bytes, string $caption ): ?array {
+		try {
+			$renderer = $this->renderer();
+			if ( 'og' === $role ) {
+				$variant = $renderer->compose_og( $bytes, $caption );
+			} elseif ( 'square' === $role ) {
+				$variant = $renderer->compose_square( $bytes, $caption );
+			} else {
+				$variant = $renderer->compose_featured( $bytes );
+			}
+
+			if ( '' === (string) ( $variant['bytes'] ?? '' ) ) {
+				$this->warn_once( sprintf( 'Imagick render for %s variant returned no bytes — degrading.', $role ) );
+				return null;
+			}
+			$variant['role'] = $role;
+
+			return $variant;
+		} catch ( \Throwable $e ) {
+			$this->warn_once( sprintf( 'Imagick render failed for %s variant: %s', $role, $e->getMessage() ) );
+			return null;
+		}
+	}
+
+	/**
+	 * Resolve the capability rung: cached probe + override filter. The
+	 * same-named filter lets tests/ops force a rung (e.g. 'none').
+	 *
+	 * @return string One of the CAP_* constants.
+	 */
+	private function resolve_capability(): string {
+		$fingerprint = md5(
+			PHP_VERSION . '|' . ( extension_loaded( 'imagick' ) ? 'im1' : 'im0' ) . '|' . ( extension_loaded( 'gd' ) ? 'gd1' : 'gd0' )
+		);
+
+		$cached = get_option( self::OPTION_CAPABILITY, array() );
+		if ( is_array( $cached ) && ( $cached['fingerprint'] ?? '' ) === $fingerprint && isset( $cached['capability'] ) ) {
+			$capability = (string) $cached['capability'];
+		} else {
+			$capability = $this->probe_capability();
+			update_option(
+				self::OPTION_CAPABILITY,
+				array(
+					'fingerprint' => $fingerprint,
+					'capability'  => $capability,
+				),
+				false
+			);
+		}
+
+		$capability = (string) apply_filters( 'prautoblogger_image_compose_capability', $capability );
+
+		return in_array( $capability, array( self::CAP_IMAGICK, self::CAP_GD, self::CAP_NONE ), true )
+			? $capability
+			: self::CAP_NONE;
+	}
+
+	/**
+	 * Probe the host for the best available rung (uncached).
+	 * @return string One of the CAP_* constants.
+	 */
+	private function probe_capability(): string {
+		if ( PRAutoBlogger_Image_Composer_Canvas::is_imagick_usable( $this->fonts_dir() . 'Poppins-Bold.ttf' ) ) {
+			return self::CAP_IMAGICK;
+		}
+
+		$png_crop = array(
+			'mime_type' => 'image/png',
+			'methods'   => array( 'resize', 'crop' ),
+		);
+		if ( function_exists( 'wp_image_editor_supports' ) && wp_image_editor_supports( $png_crop ) ) {
+			return self::CAP_GD;
+		}
+
+		return self::CAP_NONE;
+	}
+
+	/**
+	 * Lazily build the Imagick renderer with filtered layout + asset paths.
+	 * @return PRAutoBlogger_Image_Composer_Imagick
+	 */
+	private function renderer(): PRAutoBlogger_Image_Composer_Imagick {
+		if ( null === $this->renderer ) {
+			$this->renderer = new PRAutoBlogger_Image_Composer_Imagick(
+				$this->layout(),
+				dirname( __DIR__, 2 ) . '/assets/brand/',
+				$this->fonts_dir()
+			);
+		}
+		return $this->renderer;
+	}
+
+	/**
+	 * Layout geometry: pure defaults behind the documented override filter.
+	 * @return array<string, array<string, mixed>>
+	 */
+	private function layout(): array {
+		return (array) apply_filters( 'prautoblogger_image_compose_layout', PRAutoBlogger_Image_Composer_Layout::defaults() );
+	}
+
+	/**
+	 * Bundled font directory (path-derived, no constants — unit-test safe).
+	 * @return string Absolute path with trailing slash.
+	 */
+	private function fonts_dir(): string {
+		return dirname( __DIR__, 2 ) . '/assets/fonts/';
+	}
+
+	/**
+	 * Variant roles from settings, whitelisted at point of use.
+	 * @return string[] Subset of ['og', 'square'], deduplicated, in config order.
+	 */
+	private function configured_variants(): array {
+		$raw   = (string) get_option( self::OPTION_VARIANTS, 'og,square' );
+		$roles = array();
+		foreach ( explode( ',', $raw ) as $piece ) {
+			$piece = strtolower( trim( $piece ) );
+			if ( in_array( $piece, array( 'og', 'square' ), true ) && ! in_array( $piece, $roles, true ) ) {
+				$roles[] = $piece;
+			}
+		}
+		return $roles;
+	}
+
+	/**
+	 * Build the pass-through featured variant from the provider result.
+	 * @param array $image_data Provider result.
+	 * @return array{bytes: string, mime_type: string, width: int, height: int, role: string}
+	 */
+	private function passthrough_variant( array $image_data ): array {
+		return array(
+			'bytes'     => (string) ( $image_data['bytes'] ?? '' ),
+			'mime_type' => (string) ( $image_data['mime_type'] ?? 'image/png' ),
+			'width'     => (int) ( $image_data['width'] ?? 0 ),
+			'height'    => (int) ( $image_data['height'] ?? 0 ),
+			'role'      => 'featured',
+		);
+	}
+
+	/**
+	 * Log a degradation WARNING once per run (one row is enough for ops).
+	 * @param string $message Warning text.
+	 */
+	private function warn_once( string $message ): void {
+		if ( self::$warned_this_run ) {
+			return;
+		}
+		self::$warned_this_run = true;
+		PRAutoBlogger_Logger::instance()->warning( $message, 'image_composer' );
+	}
+
+	/** Reset per-run state (unit tests only). */
+	public static function reset_run_state(): void {
+		self::$warned_this_run = false;
+	}
+}

includes/core/class-image-media-sideloader.php

@@ -36,11 +36,13 @@ class PRAutoBlogger_Image_Media_Sideloader {
 	 *     latency_ms: int,
 	 * } $image_data Raw image bytes + metadata from PRAutoBlogger_Image_Provider_Interface.
 	 * @param int    $post_id Target post ID to attach the image to.
-	 * @param string $alt_text Alt text for the image (from the generation prompt).
+	 * @param string $alt_text Alt text for the image (the editorial caption).
+	 * @param string $filename_suffix Optional role hint appended to the filename
+	 *                                (e.g. 'og', 'square' for composed variants).
 	 *
 	 * @return int|\WP_Error Attachment ID on success, WP_Error on failure.
 	 */
-	public function sideload_image( array $image_data, int $post_id, string $alt_text = '' ) {
+	public function sideload_image( array $image_data, int $post_id, string $alt_text = '', string $filename_suffix = '' ) {
 		// WordPress media functions live in wp-admin/includes/ and are NOT
 		// loaded automatically in cron or REST contexts. Load them if missing.
 		// Why: WP-Cron runs as a frontend request, so admin-only files like
@@ -64,7 +66,7 @@ class PRAutoBlogger_Image_Media_Sideloader {
 
 		// Prepare file array for media_handle_sideload().
 		$file_array = array(
-			'name'     => $this->generate_filename( $image_data['model'], $image_data['width'], $image_data['height'] ),
+			'name'     => $this->generate_filename( $image_data['model'], $image_data['width'], $image_data['height'], $filename_suffix ),
 			'tmp_name' => $temp_file,
 		);
 
@@ -135,16 +137,18 @@ class PRAutoBlogger_Image_Media_Sideloader {
 	 * @param string $model Model name (e.g., 'flux-1-schnell').
 	 * @param int    $width Image width.
 	 * @param int    $height Image height.
+	 * @param string $suffix Optional role hint (e.g. 'og', 'square'); back-compat default ''.
 	 *
 	 * @return string Sanitized filename.
 	 */
-	private function generate_filename( string $model, int $width, int $height ): string {
+	private function generate_filename( string $model, int $width, int $height, string $suffix = '' ): string {
 		$base = sprintf(
-			'prautoblogger_%s_%dx%d_%s',
+			'prautoblogger_%s_%dx%d_%s%s',
 			sanitize_title( $model ),
 			$width,
 			$height,
-			gmdate( 'Y-m-d_H-i-s' )
+			gmdate( 'Y-m-d_H-i-s' ),
+			'' !== $suffix ? '_' . sanitize_title( $suffix ) : ''
 		);
 
 		return $base . '.png'; // Default to PNG — most image models output PNG.

includes/core/class-image-pipeline.php

@@ -8,13 +8,17 @@ declare(strict_types=1);
  *
  * Generates two images per article (A/B): Image A (article-driven) as featured
  * image, Image B (source-driven) in post meta. Each is independently fallible.
+ * Since v0.17.0 every result passes through the deterministic image composer
+ * (branded variants for A, corner mark for B) before sideloading; composition
+ * degrades gracefully and never blocks a publish.
  *
  * Triggered by: PRAutoBlogger_Pipeline_Runner after publisher creates the post.
- * Dependencies: Image provider, Prompt builder, Sideloader, Cost tracker, Logger.
+ * Dependencies: Image provider, Prompt builder, Composer, Attacher, Cost tracker, Logger.
  *
  * @see core/class-pipeline-runner.php       — Calls this after publisher.
  * @see core/class-image-prompt-builder.php  — Prompt generation (scene + caption).
- * @see core/class-image-media-sideloader.php — Media library integration.
+ * @see core/class-image-composer.php        — Deterministic variant composition.
+ * @see core/class-image-attacher.php        — Sideloading + variant meta-linking.
  */
 class PRAutoBlogger_Image_Pipeline {
 
@@ -34,26 +38,35 @@ class PRAutoBlogger_Image_Pipeline {
 	private PRAutoBlogger_Image_Media_Sideloader $sideloader;
 	/** @var PRAutoBlogger_Cost_Tracker Logs image generation spend. */
 	private PRAutoBlogger_Cost_Tracker $cost_tracker;
+	/** @var PRAutoBlogger_Image_Composer_Interface Composes branded variants pre-sideload. */
+	private PRAutoBlogger_Image_Composer_Interface $composer;
+	/** @var PRAutoBlogger_Image_Attacher Sideloads + meta-links results and variants. */
+	private PRAutoBlogger_Image_Attacher $attacher;
+	/** @var PRAutoBlogger_Opik_Trace_Context|null Optional tracing context. */
+	private ?PRAutoBlogger_Opik_Trace_Context $trace_context;
 
 	/**
-	 * Construct with dependencies.
-	 *
-	 * When no provider is injected, the constructor reads the
-	 * `prautoblogger_image_provider` setting and instantiates the
-	 * matching concrete class ('runware' or 'openrouter').
+	 * Construct with dependencies. When no provider is injected, the
+	 * `prautoblogger_image_provider` setting picks the concrete class
+	 * ('runware' or 'openrouter').
 	 *
 	 * @param PRAutoBlogger_Image_Provider_Interface|null $provider Optional provider override.
 	 * @param PRAutoBlogger_Cost_Tracker|null             $cost_tracker Optional cost tracker.
+	 * @param PRAutoBlogger_Opik_Trace_Context|null       $trace_context Optional tracing context.
+	 * @param PRAutoBlogger_Image_Composer_Interface|null $composer Optional composer override.
 	 */
 	public function __construct(
 		?PRAutoBlogger_Image_Provider_Interface $provider = null,
 		?PRAutoBlogger_Cost_Tracker $cost_tracker = null,
-		?PRAutoBlogger_Opik_Trace_Context $trace_context = null
+		?PRAutoBlogger_Opik_Trace_Context $trace_context = null,
+		?PRAutoBlogger_Image_Composer_Interface $composer = null
 	) {
 		$this->provider       = $provider ?? self::create_default_provider();
 		$this->prompt_builder = new PRAutoBlogger_Image_Prompt_Builder( $trace_context );
 		$this->sideloader     = new PRAutoBlogger_Image_Media_Sideloader();
 		$this->cost_tracker   = $cost_tracker ?? new PRAutoBlogger_Cost_Tracker();
+		$this->composer       = $composer ?? new PRAutoBlogger_Image_Composer();
+		$this->attacher       = new PRAutoBlogger_Image_Attacher( $this->sideloader, $this->cost_tracker );
 		$this->trace_context  = $trace_context;
 	}
 
@@ -149,12 +162,14 @@ class PRAutoBlogger_Image_Pipeline {
 				->retry_blocked_slots( $post_id, $batch_requests, $batch_results, $captions, $article_data, $source_data );
 		}
 
+		$title = (string) ( $article_data['post_title'] ?? $article_data['suggested_title'] ?? '' );
+
 		// Process Image A result.
-		$this->process_image_a( $post_id, $batch_results, $captions, $result );
+		$this->process_slot( 'image_a', $post_id, $batch_results, $captions, $title, $result );
 
 		// Process Image B result (if requested).
 		if ( isset( $batch_results['image_b'] ) ) {
-			$this->process_image_b( $post_id, $batch_results, $captions, $result );
+			$this->process_slot( 'image_b', $post_id, $batch_results, $captions, $title, $result );
 		} elseif ( null === $source_data || empty( $source_data ) ) {
 			PRAutoBlogger_Logger::instance()->info(
 				sprintf( 'Image B skipped for post %d: no source data.', $post_id ),
@@ -166,142 +181,98 @@ class PRAutoBlogger_Image_Pipeline {
 	}
 
 	/**
-	 * Process Image A batch result: sideload, set featured image, insert caption.
+	 * Process one slot's batch result: compose, sideload, link to the post.
 	 *
-	 * @param int   $post_id       Post ID.
-	 * @param array $batch_results Keyed results from generate_image_batch().
-	 * @param array $captions      Keyed captions from prompt builder.
-	 * @param array $result        Pipeline result array (modified by reference).
+	 * Image A becomes the featured image (role meta, caption prepend, and
+	 * composed OG/square variants meta-linked); Image B is stored in post
+	 * meta with a corner mark only. Alt text is the editorial caption
+	 * (v0.17.0 fix — the model name used to leak here).
+	 *
+	 * @param string $slot          'image_a' or 'image_b'.
+	 * @param int    $post_id       Post ID.
+	 * @param array  $batch_results Keyed results from generate_image_batch().
+	 * @param array  $captions      Keyed captions from prompt builder.
+	 * @param string $title         Post title (composer context).
+	 * @param array  $result        Pipeline result array (modified by reference).
 	 */
-	private function process_image_a( int $post_id, array $batch_results, array $captions, array &$result ): void {
-		$image_data = $batch_results['image_a'] ?? null;
+	private function process_slot( string $slot, int $post_id, array $batch_results, array $captions, string $title, array &$result ): void {
+		$label      = 'image_a' === $slot ? 'Image A' : 'Image B';
+		$image_data = $batch_results[ $slot ] ?? null;
+
 		if ( ! $image_data || isset( $image_data['error'] ) ) {
-			$err_msg            = $image_data['error'] ?? 'Image A missing from batch results.';
+			$err_msg            = $image_data['error'] ?? sprintf( '%s missing from batch results.', $label );
 			$result['errors'][] = $err_msg;
 			// Log at WARNING so the path is visible even if the outer catch in the
 			// caller doesn't fire. See thread image-mime-bug Issue 2.
 			PRAutoBlogger_Logger::instance()->warning(
-				sprintf( 'Image A generation failed for post %d: %s', $post_id, $err_msg ),
+				sprintf( '%s generation failed for post %d: %s', $label, $post_id, $err_msg ),
 				'image_pipeline'
 			);
 			return;
 		}
 
-		$attachment_id = $this->sideload_and_log( $image_data, $post_id, 'image_a', 'Image A' );
+		$caption  = (string) ( $captions[ $slot ] ?? '' );
+		$variants = $this->compose_variants( $image_data, $post_id, $caption, $title, $slot );
+		$featured = array_merge( $image_data, array_shift( $variants ) );
+
+		$attachment_id = $this->attacher->sideload_and_log( $featured, $post_id, $slot, $label, $caption );
 		if ( is_wp_error( $attachment_id ) ) {
 			$result['errors'][] = $attachment_id->get_error_message();
 			return;
 		}
 
-		$result['image_a_id'] = $attachment_id;
-		$result['cost_usd']  += $image_data['cost_usd'];
-		set_post_thumbnail( $post_id, $attachment_id );
+		$result[ $slot . '_id' ] = $attachment_id;
+		$result['cost_usd']     += $image_data['cost_usd'];
 
-		if ( '' !== ( $captions['image_a'] ?? '' ) ) {
-			update_post_meta( $attachment_id, '_prautoblogger_image_caption', $captions['image_a'] );
-			$this->prepend_caption_to_post( $post_id, $attachment_id, $captions['image_a'] );
+		if ( '' !== $caption ) {
+			update_post_meta( $attachment_id, '_prautoblogger_image_caption', $caption );
+		}
+
+		if ( 'image_a' === $slot ) {
+			set_post_thumbnail( $post_id, $attachment_id );
+			update_post_meta( $attachment_id, '_prautoblogger_image_role', 'featured' );
+			if ( '' !== $caption ) {
+				$this->attacher->prepend_caption_to_post( $post_id, $attachment_id, $caption );
+			}
+			$this->attacher->attach_variants( $variants, $post_id, $attachment_id, $caption, (string) ( $image_data['model'] ?? 'unknown' ) );
+		} else {
+			update_post_meta( $post_id, '_prautoblogger_image_b_id', $attachment_id );
 		}
 	}
 
 	/**
-	 * Process Image B batch result: sideload, store meta.
+	 * Run the composer with a hard safety net: any failure (composer bugs
+	 * included — its own internals already degrade) falls back to passing
+	 * the base image through, so composition can never fail a publish.
 	 *
-	 * @param int   $post_id       Post ID.
-	 * @param array $batch_results Keyed results from generate_image_batch().
-	 * @param array $captions      Keyed captions from prompt builder.
-	 * @param array $result        Pipeline result array (modified by reference).
+	 * @param array  $image_data Provider result for one slot.
+	 * @param int    $post_id    Post ID (composer context).
+	 * @param string $caption    Editorial caption (composer context).
+	 * @param string $title      Post title (composer context).
+	 * @param string $slot       'image_a' or 'image_b'.
+	 * @return array<int, array<string, mixed>> Featured-first variant list (never empty).
 	 */
-	private function process_image_b( int $post_id, array $batch_results, array $captions, array &$result ): void {
-		$image_data = $batch_results['image_b'] ?? null;
-		if ( ! $image_data || isset( $image_data['error'] ) ) {
-			$err_msg            = $image_data['error'] ?? 'Image B missing from batch results.';
-			$result['errors'][] = $err_msg;
-			// Log at WARNING so the path is visible even if the outer catch in the
-			// caller doesn't fire. See thread image-mime-bug Issue 2.
-			PRAutoBlogger_Logger::instance()->warning(
-				sprintf( 'Image B generation failed for post %d: %s', $post_id, $err_msg ),
-				'image_pipeline'
+	private function compose_variants( array $image_data, int $post_id, string $caption, string $title, string $slot ): array {
+		try {
+			$variants = $this->composer->compose(
+				$image_data,
+				array(
+					'post_id' => $post_id,
+					'caption' => $caption,
+					'title'   => $title,
+					'slot'    => $slot,
+				)
+			);
+			if ( ! empty( $variants ) ) {
+				return $variants;
+			}
+		} catch ( \Throwable $e ) {
+			PRAutoBlogger_Logger::instance()->warning(
+				'Image composition failed, publishing original image: ' . $e->getMessage(),
+				'image_composer'
 			);
-			return;
 		}
 
-		$attachment_id = $this->sideload_and_log( $image_data, $post_id, 'image_b', 'Image B' );
-		if ( is_wp_error( $attachment_id ) ) {
-			$result['errors'][] = $attachment_id->get_error_message();
-			return;
-		}
-
-		$result['image_b_id'] = $attachment_id;
-		$result['cost_usd']  += $image_data['cost_usd'];
-		update_post_meta( $post_id, '_prautoblogger_image_b_id', $attachment_id );
-
-		if ( '' !== ( $captions['image_b'] ?? '' ) ) {
-			update_post_meta( $attachment_id, '_prautoblogger_image_caption', $captions['image_b'] );
-		}
-	}
-
-	/**
-	 * Sideload image bytes into the media library and log the cost.
-	 *
-	 * @param array  $image_data Provider result with bytes, model, cost_usd.
-	 * @param int    $post_id    Post ID.
-	 * @param string $slot       Cost-tracking slot ('image_a' or 'image_b').
-	 * @param string $label      Human-readable label for logs.
-	 * @return int|\WP_Error Attachment ID on success.
-	 */
-	private function sideload_and_log( array $image_data, int $post_id, string $slot, string $label ) {
-		$attachment_id = $this->sideloader->sideload_image(
-			$image_data,
-			$post_id,
-			substr( $image_data['model'] ?? 'image', 0, 100 )
-		);
-
-		if ( is_wp_error( $attachment_id ) ) {
-			return $attachment_id;
-		}
-
-		$this->cost_tracker->log_image_generation(
-			$image_data['cost_usd'],
-			$image_data['model'] ?? 'unknown',
-			$post_id,
-			$slot
-		);
-
-		PRAutoBlogger_Logger::instance()->info(
-			sprintf( '%s for post %d (att %d, $%.4f)', $label, $post_id, $attachment_id, $image_data['cost_usd'] ),
-			'image_pipeline'
-		);
-
-		return $attachment_id;
-	}
-
-	/**
-	 * Prepend the comic caption as styled text at the top of the post content.
-	 *
-	 * Only inserts the caption — NOT the image. The theme already displays the
-	 * featured image, so embedding it again would cause a duplicate.
-	 *
-	 * @param int    $post_id Post ID.
-	 * @param int    $attachment_id Featured image attachment ID (for meta storage only).
-	 * @param string $caption Caption text (the comic punchline).
-	 */
-	private function prepend_caption_to_post( int $post_id, int $attachment_id, string $caption ): void {
-		$post = get_post( $post_id );
-		if ( ! $post ) {
-			return;
-		}
-
-		// Caption-only block — the theme handles the featured image display.
-		$caption_html = sprintf(
-			'<p class="prautoblogger-comic-caption" style="text-align:center;font-style:italic;color:#555;font-size:1.1em;margin:0 0 2em 0;">— "%s"</p>',
-			esc_html( $caption )
-		);
-
-		wp_update_post(
-			array(
-				'ID'           => $post_id,
-				'post_content' => $caption_html . "\n\n" . $post->post_content,
-			)
-		);
+		return array( array_merge( $image_data, array( 'role' => 'featured' ) ) );
 	}
 }

includes/core/class-image-prompt-builder.php

@@ -6,13 +6,16 @@ declare(strict_types=1);
  *
  * Builds image prompts from article content or source data.
  *
- * Uses a cheap LLM (via OpenRouter) to distill article content into concise
- * visual scene descriptions optimised for image generation. Falls back to rule-based
+ * Uses a cheap LLM (via OpenRouter) to distill article content into a concise
+ * 1-2 sentence editorial topic/mechanism summary, then substitutes that summary
+ * into the admin-editable editorial style template (the {{ topic_summary }}
+ * slot) to produce a text-free image-gen prompt. Falls back to rule-based
  * synthesis if the LLM call fails, so image generation never blocks on a
  * prompt-rewriting outage.
  *
  * Triggered by: PRAutoBlogger_Image_Pipeline during content generation run.
  * Dependencies: PRAutoBlogger_OpenRouter_Provider (LLM call),
+ *               PRAutoBlogger_Image_Template_Filler (template substitution),
  *               PRAutoBlogger_Cost_Tracker (logs prompt-rewrite cost),
  *               PRAutoBlogger_Logger (diagnostics).
  *
@@ -27,34 +30,39 @@ class PRAutoBlogger_Image_Prompt_Builder {
 	 * prompts. Exposed as a `public const` so the admin-settings layer can
 	 * use it as the default value for `prautoblogger_image_prompt_instructions`.
 	 * The option, when non-empty, wins at call time (see rewrite_via_llm).
+	 *
+	 * Editorial pivot (v0.16.0): the model emits a concise topic/mechanism
+	 * summary as the SCENE — concrete, single centered focal subject, no text,
+	 * no people-as-gag, no logos — which the prompt builder substitutes into
+	 * the editorial style template's {{ topic_summary }} slot. The CAPTION line
+	 * is preserved unchanged for the existing HTML-caption-below-image path.
 	 */
 	public const REWRITER_SYSTEM_PROMPT = <<<'PROMPT'
-You are a comedy writer and single-panel cartoon creator, like Gary Larson (The Far Side) meets science humor.
+You write subject descriptions for a text-free editorial science illustration about peptides, supplements, or biohacking.
 
-Given an article title and summary about peptides, supplements, or biohacking, create a SINGLE-PANEL COMIC concept. Output TWO parts separated by a blank line:
+Given an article title and summary, output TWO parts separated by a blank line:
 
-SCENE: One sentence describing the visual gag — a funny, absurd, or ironic situation related to the article's topic. Favor CONCRETE, HUMAN-SCALE scenes: people reacting to things, doctors and patients, scientists in a lab, gym bros with peptide vials, partners at a kitchen table, ordinary objects in ordinary rooms. Keep it simple — one clear visual joke, 1-3 characters max.
+SCENE: A concise 1-2 sentence description of the article's core topic or mechanism, written as the SUBJECT of a single editorial illustration. Name ONE concrete, centered focal subject and the few supporting visual elements around it (e.g. a labelled-free vial and dropper, a stylised receptor on a cell membrane, a molecular chain, a dosing syringe, an organ cross-section). Favor a clear central focal point with margin around it so the image crops well. This is image-gen direction, not prose.
 
-CAPTION: A short, punchy caption or speech bubble line (under 15 words) that delivers the punchline. The humor should be dry, nerdy, and accessible — the reader should chuckle even if they only half-understand the science.
+CAPTION: A short, informative caption line (under 15 words) for display as HTML text below the image. Plain and editorial, not a joke.
 
 Rules:
-- The joke MUST relate to the article's actual subject matter, not generic science humor
-- DO NOT personify molecules, peptides, hormones, proteins, or other chemical structures (no "anthropomorphic molecule", no "cartoon hormone"). Image models render anthropomorphized chemistry as incoherent blobs. If the article is about a substance, show a PERSON reacting to or using the substance; if the article is abstract (a mechanism, a process, a concept), fall back on a human observer reacting to its effect.
-- Characters can have simple cartoon faces (round heads, dot eyes, expressive eyebrows)
-- Keep the scene physically simple — few objects, clear staging, easy to read at thumbnail size
-- The caption should work as a standalone joke even without the image
-- No logos, watermarks, or branding
+- The SCENE must depict the article's actual subject/mechanism, not a generic science scene.
+- NO text, words, captions, speech bubbles, labels, or logos described in the SCENE — the illustration is text-free; text is rendered separately.
+- NO people used as a visual gag and NO cartoon/comic framing. A human anatomical element (a cell, an organ, a hand holding a vial) is fine if it is the legitimate subject.
+- Do NOT personify molecules, peptides, hormones, or proteins (no "smiling molecule"); depict them as clean stylised diagrams or structures.
+- Keep the staging simple with one clear focal subject, readable at small sizes.
 - Output ONLY the scene and caption. No preamble, no explanation.
 
 Example output format:
-A muscular gym bro stares, deflated, at a tiny glass vial in his hand while his friend squats a barbell effortlessly in the background.
+A single glass peptide vial on a clean surface with a fine dropper above it, a faint stylised molecular chain arcing behind as a backdrop, centered with generous negative space.
 
-"They told me the peptide did the work, not the squats."
+A concentrated look at how the compound is prepared before use.
 PROMPT;
 
 	/**
-	 * Max tokens for the rewriter response. Comic concepts need more room
-	 * for the scene description plus the caption punchline.
+	 * Max tokens for the rewriter response. Enough room for the 1-2 sentence
+	 * topic/mechanism summary plus the short editorial caption line.
 	 */
 	private const REWRITER_MAX_TOKENS = 180;
 
@@ -85,8 +93,9 @@ PROMPT;
 	 * Build a visual prompt from finished article content.
 	 *
 	 * Tries LLM rewriting first; falls back to rule-based synthesis on
-	 * failure. Splits scene (for image gen) from caption (HTML below the
-	 * image) and appends the style suffix.
+	 * failure. Splits scene (the topic summary, for image gen) from caption
+	 * (HTML below the image) and substitutes the scene into the editorial
+	 * style template's {{ topic_summary }} slot.
 	 *
 	 * @param array{post_title?: string, post_content?: string, suggested_title?: string} $article_data
 	 * @return array{prompt: string, caption: string}
@@ -98,10 +107,8 @@ PROMPT;
 
 		$parsed = $this->rewrite_via_llm( $title, $first_para );
 
-		$style_suffix = $this->get_style_suffix();
-
 		return array(
-			'prompt'  => trim( $parsed['scene'] . ' ' . $style_suffix ),
+			'prompt'  => PRAutoBlogger_Image_Template_Filler::fill( $parsed['scene'] ),
 			'caption' => $parsed['caption'],
 		);
 	}
@@ -120,10 +127,8 @@ PROMPT;
 
 		$parsed = $this->rewrite_via_llm( $title, $context );
 
-		$style_suffix = $this->get_style_suffix();
-
 		return array(
-			'prompt'  => trim( $parsed['scene'] . ' ' . $style_suffix ),
+			'prompt'  => PRAutoBlogger_Image_Template_Filler::fill( $parsed['scene'] ),
 			'caption' => $parsed['caption'],
 		);
 	}
@@ -260,10 +265,9 @@ PROMPT;
 	 * @return array{prompt: string, caption: string}
 	 */
 	public function build_fallback_prompt( string $title ): array {
-		$parsed       = PRAutoBlogger_Image_Scene_Parser::synthesize_visual_concepts_fallback( $title, '' );
-		$style_suffix = $this->get_style_suffix();
+		$parsed = PRAutoBlogger_Image_Scene_Parser::synthesize_visual_concepts_fallback( $title, '' );
 		return array(
-			'prompt'  => trim( $parsed['scene'] . ' ' . $style_suffix ),
+			'prompt'  => PRAutoBlogger_Image_Template_Filler::fill( $parsed['scene'] ),
 			'caption' => $parsed['caption'],
 		);
 	}
@@ -281,20 +285,4 @@ PROMPT;
 		$override = (string) get_option( 'prautoblogger_image_prompt_instructions', '' );
 		return '' !== trim( $override ) ? $override : self::REWRITER_SYSTEM_PROMPT;
 	}
-
-	/**
-	 * Get image style suffix with empty-string safeguard.
-	 *
-	 * Treats both absent and empty string as "use default" to prevent
-	 * silent style loss if the admin settings field is saved empty.
-	 *
-	 * @return string The style suffix with safe fallback.
-	 */
-	private function get_style_suffix(): string {
-		$style_suffix = (string) get_option( 'prautoblogger_image_style_suffix', '' );
-		if ( '' === trim( $style_suffix ) ) {
-			$style_suffix = PRAUTOBLOGGER_DEFAULT_IMAGE_STYLE_SUFFIX;
-		}
-		return $style_suffix;
-	}
 }

includes/core/class-image-scene-parser.php

@@ -70,22 +70,25 @@ class PRAutoBlogger_Image_Scene_Parser {
 	/**
 	 * Rule-based fallback when LLM rewriting is unavailable.
 	 *
-	 * Kept deliberately simple — this only runs if OpenRouter is down.
+	 * Kept deliberately simple — this only runs if OpenRouter is down. Produces
+	 * a text-free editorial-illustration subject (not a comic) so the prompt
+	 * builder always has a non-empty topic summary to substitute into the
+	 * style template, never shipping a blank prompt to the provider (brief A6).
 	 *
 	 * @param string $title           Main heading / topic.
 	 * @param string $supporting_text Additional context.
 	 * @return array{scene: string, caption: string} Scene for image gen, caption for HTML.
 	 */
 	public static function synthesize_visual_concepts_fallback( string $title, string $supporting_text ): array {
-		// Fallback produces a simple comic concept when the LLM is unavailable.
+		// Fallback produces a simple editorial-illustration subject when the LLM is unavailable.
 		$scene = sprintf(
-			'A cartoon scientist in a lab coat looking bewildered while examining something related to: %s.',
+			'A clean, centered editorial science illustration representing the topic of %s, with a single clear focal subject and generous negative space.',
 			$title
 		);
 
 		return array(
 			'scene'   => trim( $scene ),
-			'caption' => 'Science is full of surprises.',
+			'caption' => '',
 		);
 	}
 }

includes/core/class-image-template-filler.php

@@ -0,0 +1,185 @@
+<?php
+declare(strict_types=1);
+
+/**
+ * phpcs:ignore WordPress.Files.FileName.InvalidClassFileName -- class naming convention differs from WordPress standard
+ *
+ * Fills the admin-editable editorial image-prompt template with the
+ * rewriter-produced topic summary, replacing the old "scene + style suffix"
+ * concatenation.
+ *
+ * The template (option `prautoblogger_image_style_template`, default
+ * PRAUTOBLOGGER_DEFAULT_IMAGE_STYLE_TEMPLATE) contains exactly one
+ * `{{ topic_summary }}` token. This class:
+ *   - resolves the active template (admin override wins; blank → default),
+ *   - sanitises and length-clamps the topic summary (brief A5),
+ *   - substitutes the token, and
+ *   - degrades safely (brief A5/A6) so a blank or token-only prompt is never
+ *     emitted to the image provider.
+ *
+ * Who calls it: PRAutoBlogger_Image_Prompt_Builder (static call from each of
+ *               build_article_prompt / build_source_prompt / build_fallback_prompt).
+ * Dependencies: PRAutoBlogger_Logger (diagnostics only).
+ *
+ * @see core/class-image-prompt-builder.php — Sole caller.
+ * @see ARCHITECTURE.md                      — Image generation data flow.
+ */
+class PRAutoBlogger_Image_Template_Filler {
+
+	/** The single substitution token the template must contain. */
+	public const TOKEN = '{{ topic_summary }}';
+
+	/**
+	 * Max characters retained from the rewriter topic summary before it is
+	 * substituted into the template. Keeps the final provider prompt bounded
+	 * even if the rewriter ignores its length guidance.
+	 */
+	public const MAX_SUMMARY_CHARS = 320;
+
+	/**
+	 * Build the final image-generation prompt from a rewriter scene.
+	 *
+	 * @param string $scene Raw topic/mechanism summary from the rewriter (the
+	 *                      "scene" half of the scene/caption contract).
+	 * @return string Provider-ready prompt; never empty.
+	 */
+	public static function fill( string $scene ): string {
+		$template = self::resolve_template();
+		$summary  = self::sanitize_summary( $scene );
+
+		// Brief A6: never ship a blank or token-only prompt. If the rewriter
+		// produced nothing usable, return the template with the token removed
+		// only as a last resort — but the caller guards this by passing a
+		// rule-based fallback scene, so an empty summary here is unexpected.
+		if ( '' === $summary ) {
+			PRAutoBlogger_Logger::instance()->warning(
+				'Editorial prompt fill received an empty topic summary; emitting style-only prompt.',
+				'image_template_filler'
+			);
+			return self::strip_token( $template );
+		}
+
+		$token_count = substr_count( $template, self::TOKEN );
+
+		if ( 1 === $token_count ) {
+			return trim( str_replace( self::TOKEN, $summary, $template ) );
+		}
+
+		// Brief A5: admin removed or duplicated the token. Fall back to
+		// appending the summary to the style text and log a warning rather
+		// than shipping a malformed prompt.
+		PRAutoBlogger_Logger::instance()->warning(
+			sprintf(
+				'Image style template has %d "%s" tokens (expected 1); appending summary instead of substituting.',
+				$token_count,
+				self::TOKEN
+			),
+			'image_template_filler'
+		);
+
+		$base = self::strip_token( $template );
+		return trim( $base . ' ' . $summary );
+	}
+
+	/**
+	 * Sanitise and validate the admin-submitted style template on save.
+	 *
+	 * Multi-line, so sanitised with sanitize_textarea_field() (not
+	 * sanitize_text_field(), which would strip newlines). Per brief A5 the
+	 * template must contain exactly one TOKEN; otherwise the previous value is
+	 * kept and a settings error is surfaced. A blank submission falls back to
+	 * the editorial default so image generation can never be bricked.
+	 *
+	 * @param string $value Submitted template.
+	 * @return string Sanitised, validated template.
+	 */
+	public static function sanitize_for_save( string $value ): string {
+		$clean = sanitize_textarea_field( $value );
+
+		if ( '' === trim( $clean ) ) {
+			return PRAUTOBLOGGER_DEFAULT_IMAGE_STYLE_TEMPLATE;
+		}
+
+		$token_count = substr_count( $clean, self::TOKEN );
+		if ( 1 !== $token_count ) {
+			add_settings_error(
+				'prautoblogger_image_style_template',
+				'prautoblogger_image_style_template_token',
+				sprintf(
+					/* translators: 1: required token, 2: number of tokens found. */
+					esc_html__( 'The Style Template must contain exactly one %1$s token (found %2$d). Keeping the previous value.', 'prautoblogger' ),
+					esc_html( self::TOKEN ),
+					(int) $token_count
+				)
+			);
+			return (string) get_option( 'prautoblogger_image_style_template', PRAUTOBLOGGER_DEFAULT_IMAGE_STYLE_TEMPLATE );
+		}
+
+		return $clean;
+	}
+
+	/**
+	 * Resolve the active template: admin override wins; blank → default.
+	 *
+	 * @return string Non-empty template string.
+	 */
+	private static function resolve_template(): string {
+		$override = (string) get_option( 'prautoblogger_image_style_template', '' );
+		if ( '' !== trim( $override ) ) {
+			return $override;
+		}
+		return PRAUTOBLOGGER_DEFAULT_IMAGE_STYLE_TEMPLATE;
+	}
+
+	/**
+	 * Strip control characters and clamp length of the rewriter summary
+	 * (brief A5). Whitespace runs (including newlines) are collapsed to single
+	 * spaces so the summary sits cleanly inside the template.
+	 *
+	 * @param string $scene Raw rewriter scene.
+	 * @return string Sanitised, length-clamped summary (possibly empty).
+	 */
+	private static function sanitize_summary( string $scene ): string {
+		// Remove control characters (C0/C1) except via whitespace collapse below.
+		$clean = preg_replace( '/[\x00-\x1F\x7F]+/u', ' ', $scene );
+		if ( null === $clean ) {
+			// preg_replace can return null on bad UTF-8; degrade conservatively.
+			$clean = preg_replace( '/[\x00-\x1F\x7F]+/', ' ', $scene );
+			$clean = is_string( $clean ) ? $clean : '';
+		}
+
+		// Collapse whitespace runs to single spaces.
+		$collapsed = preg_replace( '/\s+/u', ' ', $clean );
+		$clean     = is_string( $collapsed ) ? $collapsed : $clean;
+		$clean     = trim( $clean );
+
+		if ( '' === $clean ) {
+			return '';
+		}
+
+		// Clamp length (multibyte-aware where available).
+		if ( function_exists( 'mb_strlen' ) ) {
+			if ( mb_strlen( $clean ) > self::MAX_SUMMARY_CHARS ) {
+				$clean = rtrim( mb_substr( $clean, 0, self::MAX_SUMMARY_CHARS ) ) . '...';
+			}
+		} elseif ( strlen( $clean ) > self::MAX_SUMMARY_CHARS ) {
+			$clean = rtrim( substr( $clean, 0, self::MAX_SUMMARY_CHARS ) ) . '...';
+		}
+
+		return $clean;
+	}
+
+	/**
+	 * Remove every occurrence of the token from a template, tidying the
+	 * leftover whitespace so the residual style text is still well-formed.
+	 *
+	 * @param string $template Template possibly containing the token.
+	 * @return string Token-free, trimmed template.
+	 */
+	private static function strip_token( string $template ): string {
+		$stripped = str_replace( self::TOKEN, '', $template );
+		$stripped = preg_replace( '/[ \t]+/', ' ', $stripped );
+		$stripped = is_string( $stripped ) ? $stripped : $template;
+		return trim( $stripped );
+	}
+}

includes/core/interface-image-composer.php

@@ -0,0 +1,50 @@
+<?php
+declare(strict_types=1);
+
+/**
+ * phpcs:ignore WordPress.Files.FileName.InvalidClassFileName -- class naming convention differs from WordPress standard
+ *
+ * Contract for image composers that turn raw provider bytes into final variants.
+ *
+ * A composer sits between the image provider (raw generated bytes) and the
+ * media sideloader. It receives one base image plus per-post context and
+ * returns one or more finished variants — the first is always the `featured`
+ * role (the bytes that become the post thumbnail), optionally followed by
+ * social variants (`og`, `square`). Implementations must NEVER throw out of
+ * compose(): on any internal failure they degrade to passing the base image
+ * through unmodified so publishing is never blocked.
+ *
+ * Triggered by: PRAutoBlogger_Image_Pipeline between batch results and sideload.
+ * Dependencies: none — this is the contract only.
+ *
+ * @see core/class-image-composer.php  — Default implementation (capability ladder).
+ * @see core/class-image-pipeline.php  — Caller.
+ * @see core/class-image-attacher.php  — Persists the returned variants.
+ */
+interface PRAutoBlogger_Image_Composer_Interface {
+
+	/**
+	 * Compose final image variant(s) from raw provider bytes.
+	 *
+	 * Side effects: implementations may read plugin options and write to the
+	 * activity log; they must not make network calls or fail the publish.
+	 *
+	 * @param array{
+	 *     bytes: string,
+	 *     mime_type: string,
+	 *     width: int,
+	 *     height: int,
+	 * } $image_data Base image bytes + metadata from the provider result.
+	 * @param array{
+	 *     post_id: int,
+	 *     caption: string,
+	 *     title: string,
+	 *     slot: string,
+	 * } $context Post ID, editorial caption, post title, and slot
+	 *            ('image_a' or 'image_b'); only image_a yields variants.
+	 *
+	 * @return array<int, array{bytes: string, mime_type: string, width: int, height: int, role: string}>
+	 *               Non-empty list; index 0 always carries role 'featured'.
+	 */
+	public function compose( array $image_data, array $context ): array;
+}

prautoblogger.php

@@ -9,7 +9,7 @@
  * Plugin Name:       PRAutoBlogger
  * Plugin URI:        https://peptiderepo.com/prautoblogger
  * Description:       Monitors social media for trending topics, generates SEO-friendly blog posts using AI, and publishes them on a daily schedule with full cost tracking and self-improvement metrics.
- * Version:           0.15.1
+ * Version:           0.17.0
  * Requires at least: 6.0
  * Requires PHP:      7.4
  * Author:            PeptideRepo
@@ -35,7 +35,7 @@ if ( ! defined( 'ABSPATH' ) ) {
 | Defined here so every file in the plugin can reference paths, versions,
 | and limits without magic strings.
 */
-define( 'PRAUTOBLOGGER_VERSION', '0.15.1' );
+define( 'PRAUTOBLOGGER_VERSION', '0.17.0' );
 define( 'PRAUTOBLOGGER_DB_VERSION', '1.1.0' );
 define( 'PRAUTOBLOGGER_PLUGIN_FILE', __FILE__ );
 define( 'PRAUTOBLOGGER_PLUGIN_DIR', plugin_dir_path( __FILE__ ) );
@@ -66,6 +66,22 @@ define(
 	'PRAUTOBLOGGER_DEFAULT_IMAGE_STYLE_SUFFIX',
 	'Style: a single-panel newspaper comic in classic black ink on white paper, simple clean linework like The Far Side or B.C., slightly yellowed newsprint texture, hand-drawn crosshatching for shading, bold panel border, warm and humorous tone, visible in a newspaper comics section. IMPORTANT: Do not render any text, captions, speech bubbles, or words inside the image.'
 );
+// Default editorial-illustration prompt template for the image generator.
+// Updated 2026-05-29 (v0.16.0): pivot from single-panel comic to text-free
+// editorial scientific illustration. The {{ topic_summary }} token is filled
+// at build time with a 1-2 sentence topic/mechanism description from the
+// rewriter LLM; the rest is brand-locked. Replaces the old Style Suffix.
+// Users may override via Settings -> Images -> Style Template. Per brief A5
+// the template must contain exactly one {{ topic_summary }} token.
+define(
+	'PRAUTOBLOGGER_DEFAULT_IMAGE_STYLE_TEMPLATE',
+	"Editorial scientific illustration, flat vector aesthetic, limited palette of\n" .
+	"teal (#1B8A92) and cream (#FAF6EE) with ink (#0D0D0D) line work and accents\n" .
+	"of orange (#FF8A3D) and lime (#7FD600). Subject: {{ topic_summary }}.\n" .
+	"Style reference: Quanta Magazine, The Pudding, scientific editorial illustration.\n" .
+	"Composition: clear focal point, balanced negative space, subtle textural detail.\n" .
+	'Mood: authoritative, clinical, calm. NO TEXT. NO PEOPLE. NO LOGOS. NO LABELS.'
+);
 // Opik observability (feature-flag gated).
 // API credentials must be defined in wp-config.php constants:
 // - PRAUTOBLOGGER_OPIK_API_KEY: API key for authentication

tests/bootstrap.php

@@ -67,11 +67,20 @@ if ( ! defined( 'PRAUTOBLOGGER_DEFAULT_IMAGE_PROVIDER' ) ) {
     define( 'PRAUTOBLOGGER_DEFAULT_IMAGE_PROVIDER', 'runware' );
 }
 
-// Default image style suffix used by ImagePromptBuilder and settings UI.
+// Default image style suffix used by legacy ImagePromptBuilder paths / settings UI.
 if ( ! defined( 'PRAUTOBLOGGER_DEFAULT_IMAGE_STYLE_SUFFIX' ) ) {
     define( 'PRAUTOBLOGGER_DEFAULT_IMAGE_STYLE_SUFFIX', 'Style: test infomercial style.' );
 }
 
+// Editorial style template (v0.16.0): default for prautoblogger_image_style_template.
+// Must contain exactly one {{ topic_summary }} token (brief A5).
+if ( ! defined( 'PRAUTOBLOGGER_DEFAULT_IMAGE_STYLE_TEMPLATE' ) ) {
+    define(
+        'PRAUTOBLOGGER_DEFAULT_IMAGE_STYLE_TEMPLATE',
+        "Editorial scientific illustration. Subject: {{ topic_summary }}. NO TEXT. NO PEOPLE. NO LOGOS. NO LABELS."
+    );
+}
+
 // WordPress database constants used in $wpdb queries.
 if ( ! defined( 'ARRAY_A' ) ) {
     define( 'ARRAY_A', 'ARRAY_A' );

tests/unit/Core/ImageAttacherTest.php

@@ -0,0 +1,176 @@
+<?php
+/**
+ * Tests for PRAutoBlogger_Image_Attacher.
+ *
+ * Validates primary sideload + cost logging (including the v0.17.0 alt-text
+ * fix: the caption, not the model name, becomes alt text) and composed
+ * variant persistence with role/base meta-linking at $0 cost.
+ *
+ * @package PRAutoBlogger\Tests\Core
+ */
+
+namespace PRAutoBlogger\Tests\Core;
+
+use PRAutoBlogger\Tests\BaseTestCase;
+use Brain\Monkey\Functions;
+
+class ImageAttacherTest extends BaseTestCase {
+
+	/** @var array Captured update_post_meta calls: [object_id, key, value]. */
+	private array $meta_calls = [];
+
+	protected function setUp(): void {
+		parent::setUp();
+
+		Functions\when( 'is_wp_error' )->alias(
+			static function ( $thing ) {
+				return $thing instanceof \WP_Error;
+			}
+		);
+		$this->meta_calls = [];
+		Functions\when( 'update_post_meta' )->alias(
+			function ( $object_id, $key, $value ) {
+				$this->meta_calls[] = [ $object_id, $key, $value ];
+				return true;
+			}
+		);
+		$this->stub_get_option( [] );
+	}
+
+	/** Helper: find a captured meta value by object id + key. */
+	private function meta_value( int $object_id, string $key ) {
+		foreach ( $this->meta_calls as $call ) {
+			if ( $call[0] === $object_id && $call[1] === $key ) {
+				return $call[2];
+			}
+		}
+		return null;
+	}
+
+	/** Helper: primary image fixture. */
+	private function image_data(): array {
+		return [
+			'bytes'      => 'featured_bytes',
+			'mime_type'  => 'image/png',
+			'width'      => 1200,
+			'height'     => 632,
+			'model'      => 'flux-1-schnell',
+			'cost_usd'   => 0.0006,
+			'latency_ms' => 1500,
+		];
+	}
+
+	/**
+	 * sideload_and_log() forwards the caption as alt text (bug fix: the model
+	 * name used to leak into alt text) and logs the generation cost once.
+	 */
+	public function test_sideload_and_log_forwards_caption_as_alt_and_logs_cost(): void {
+		$sideloader = $this->createMock( \PRAutoBlogger_Image_Media_Sideloader::class );
+		$sideloader->expects( $this->once() )
+			->method( 'sideload_image' )
+			->with( $this->image_data(), 7, 'Collagen fragments may aid joint repair' )
+			->willReturn( 42 );
+
+		$cost_tracker = $this->createMock( \PRAutoBlogger_Cost_Tracker::class );
+		$cost_tracker->expects( $this->once() )
+			->method( 'log_image_generation' )
+			->with( 0.0006, 'flux-1-schnell', 7, 'image_a' );
+
+		$attacher = new \PRAutoBlogger_Image_Attacher( $sideloader, $cost_tracker );
+		$result   = $attacher->sideload_and_log( $this->image_data(), 7, 'image_a', 'Image A', 'Collagen fragments may aid joint repair' );
+
+		$this->assertSame( 42, $result );
+	}
+
+	/**
+	 * A failed primary sideload returns the WP_Error untouched and logs no cost.
+	 */
+	public function test_sideload_and_log_propagates_error_without_cost_row(): void {
+		$error      = new \WP_Error( 'sideload_failed', 'disk full' );
+		$sideloader = $this->createMock( \PRAutoBlogger_Image_Media_Sideloader::class );
+		$sideloader->method( 'sideload_image' )->willReturn( $error );
+
+		$cost_tracker = $this->createMock( \PRAutoBlogger_Cost_Tracker::class );
+		$cost_tracker->expects( $this->never() )->method( 'log_image_generation' );
+
+		$attacher = new \PRAutoBlogger_Image_Attacher( $sideloader, $cost_tracker );
+
+		$this->assertSame( $error, $attacher->sideload_and_log( $this->image_data(), 7, 'image_a', 'Image A', 'cap' ) );
+	}
+
+	/**
+	 * attach_variants() sideloads og + square with the role as filename
+	 * suffix and the caption as alt text, writes role/base attachment meta
+	 * and the role-specific post meta, and never logs composition cost.
+	 */
+	public function test_attach_variants_meta_links_og_and_square(): void {
+		$variants = [
+			[
+				'bytes'     => 'og_bytes',
+				'mime_type' => 'image/png',
+				'width'     => 1200,
+				'height'    => 630,
+				'role'      => 'og',
+			],
+			[
+				'bytes'     => 'square_bytes',
+				'mime_type' => 'image/png',
+				'width'     => 1080,
+				'height'    => 1080,
+				'role'      => 'square',
+			],
+		];
+
+		$returned_ids = [ 'og' => 43, 'square' => 44 ];
+		$sideloader   = $this->createMock( \PRAutoBlogger_Image_Media_Sideloader::class );
+		$sideloader->expects( $this->exactly( 2 ) )
+			->method( 'sideload_image' )
+			->willReturnCallback(
+				function ( array $image_data, int $post_id, string $alt, string $suffix ) use ( $returned_ids ) {
+					$this->assertSame( 7, $post_id );
+					$this->assertSame( 'A short caption', $alt );
+					$this->assertSame( 0.0, $image_data['cost_usd'] );
+					$this->assertSame( 'flux-1-schnell', $image_data['model'] );
+					$this->assertArrayHasKey( $suffix, $returned_ids, 'filename suffix must be the role' );
+					return $returned_ids[ $suffix ];
+				}
+			);
+
+		$cost_tracker = $this->createMock( \PRAutoBlogger_Cost_Tracker::class );
+		$cost_tracker->expects( $this->never() )->method( 'log_image_generation' );
+
+		$attacher = new \PRAutoBlogger_Image_Attacher( $sideloader, $cost_tracker );
+		$attacher->attach_variants( $variants, 7, 42, 'A short caption', 'flux-1-schnell' );
+
+		$this->assertSame( 'og', $this->meta_value( 43, '_prautoblogger_image_role' ) );
+		$this->assertSame( 42, $this->meta_value( 43, '_prautoblogger_base_attachment_id' ) );
+		$this->assertSame( 43, $this->meta_value( 7, '_prautoblogger_og_image_id' ) );
+
+		$this->assertSame( 'square', $this->meta_value( 44, '_prautoblogger_image_role' ) );
+		$this->assertSame( 42, $this->meta_value( 44, '_prautoblogger_base_attachment_id' ) );
+		$this->assertSame( 44, $this->meta_value( 7, '_prautoblogger_square_image_id' ) );
+	}
+
+	/**
+	 * Unknown roles (e.g. a stray featured entry) are ignored, and a failed
+	 * variant sideload is skipped without meta writes or exceptions.
+	 */
+	public function test_attach_variants_skips_unknown_roles_and_failed_sideloads(): void {
+		$variants = [
+			[ 'bytes' => 'f', 'mime_type' => 'image/png', 'width' => 1, 'height' => 1, 'role' => 'featured' ],
+			[ 'bytes' => 'o', 'mime_type' => 'image/png', 'width' => 1200, 'height' => 630, 'role' => 'og' ],
+		];
+
+		$sideloader = $this->createMock( \PRAutoBlogger_Image_Media_Sideloader::class );
+		$sideloader->expects( $this->once() ) // Only og — featured is not a variant role here.
+			->method( 'sideload_image' )
+			->willReturn( new \WP_Error( 'sideload_failed', 'nope' ) );
+
+		$cost_tracker = $this->createMock( \PRAutoBlogger_Cost_Tracker::class );
+
+		$attacher = new \PRAutoBlogger_Image_Attacher( $sideloader, $cost_tracker );
+		$attacher->attach_variants( $variants, 7, 42, 'cap', 'model' );
+
+		$this->assertSame( [], $this->meta_calls );
+	}
+}

tests/unit/Core/ImageComposerImagickTest.php

@@ -0,0 +1,104 @@
+<?php
+/**
+ * Tests for PRAutoBlogger_Image_Composer_Imagick (real renders).
+ *
+ * These run only where ext-imagick is loaded (skipped on the standard CI
+ * matrix); the same renders are exercised by the standalone harness that
+ * produced the PR samples. Asserts the determinism contract — identical
+ * inputs yield byte-identical output in the same environment — plus the
+ * exact variant geometry.
+ *
+ * @package PRAutoBlogger\Tests\Core
+ */
+
+namespace PRAutoBlogger\Tests\Core;
+
+use PRAutoBlogger\Tests\BaseTestCase;
+
+class ImageComposerImagickTest extends BaseTestCase {
+
+	protected function setUp(): void {
+		parent::setUp();
+		if ( ! extension_loaded( 'imagick' ) ) {
+			$this->markTestSkipped( 'ext-imagick not available — renderer covered by the server-side harness.' );
+		}
+	}
+
+	/** Helper: renderer wired to the real bundled assets. */
+	private function renderer(): \PRAutoBlogger_Image_Composer_Imagick {
+		$root = dirname( __DIR__, 3 );
+
+		return new \PRAutoBlogger_Image_Composer_Imagick(
+			\PRAutoBlogger_Image_Composer_Layout::defaults(),
+			$root . '/assets/brand/',
+			$root . '/assets/fonts/'
+		);
+	}
+
+	/** Helper: deterministic 1200×632 fixture base image (gradient + disc). */
+	private function fixture_bytes(): string {
+		$image = new \Imagick();
+		$image->newPseudoImage( 1200, 632, 'gradient:#1B8A92-#FAFAF7' );
+		$draw = new \ImagickDraw();
+		$draw->setFillColor( new \ImagickPixel( '#FF8A3D' ) );
+		$draw->circle( 600, 316, 600, 470 );
+		$image->drawImage( $draw );
+		$image->setImageFormat( 'png' );
+
+		return $image->getImageBlob();
+	}
+
+	/**
+	 * Determinism: rendering the same input twice yields byte-identical
+	 * variants (metadata stripped, PNG date/time chunks excluded).
+	 */
+	public function test_same_input_renders_byte_identical_output(): void {
+		$bytes   = $this->fixture_bytes();
+		$caption = 'Collagen fragments may aid joint repair';
+
+		$first  = $this->renderer()->compose_og( $bytes, $caption );
+		$second = $this->renderer()->compose_og( $bytes, $caption );
+		$this->assertSame( hash( 'sha256', $first['bytes'] ), hash( 'sha256', $second['bytes'] ), 'OG render must be byte-stable' );
+
+		$first  = $this->renderer()->compose_square( $bytes, $caption );
+		$second = $this->renderer()->compose_square( $bytes, $caption );
+		$this->assertSame( hash( 'sha256', $first['bytes'] ), hash( 'sha256', $second['bytes'] ), 'Square render must be byte-stable' );
+
+		$first  = $this->renderer()->compose_featured( $bytes );
+		$second = $this->renderer()->compose_featured( $bytes );
+		$this->assertSame( hash( 'sha256', $first['bytes'] ), hash( 'sha256', $second['bytes'] ), 'Featured render must be byte-stable' );
+	}
+
+	/**
+	 * Variant geometry matches the spec: featured keeps base dimensions,
+	 * OG is exactly 1200×630, square exactly 1080×1080, all PNG.
+	 */
+	public function test_variant_dimensions_and_mime(): void {
+		$bytes   = $this->fixture_bytes();
+		$caption = 'Collagen fragments may aid joint repair';
+
+		$featured = $this->renderer()->compose_featured( $bytes );
+		$this->assertSame( [ 1200, 632, 'image/png', 'featured' ], [ $featured['width'], $featured['height'], $featured['mime_type'], $featured['role'] ] );
+
+		$og = $this->renderer()->compose_og( $bytes, $caption );
+		$this->assertSame( [ 1200, 630, 'image/png', 'og' ], [ $og['width'], $og['height'], $og['mime_type'], $og['role'] ] );
+
+		$square = $this->renderer()->compose_square( $bytes, $caption );
+		$this->assertSame( [ 1080, 1080, 'image/png', 'square' ], [ $square['width'], $square['height'], $square['mime_type'], $square['role'] ] );
+	}
+
+	/**
+	 * Output PNG bytes embed no date text chunks or tIME chunk, so a render
+	 * is stable across wall-clock time, not just within one process. (We
+	 * scan the raw bytes: Imagick synthesizes `date:*` image properties at
+	 * read time even for chunk-free PNGs, so getImageProperties() can't
+	 * distinguish embedded dates from synthesized ones.)
+	 */
+	public function test_output_contains_no_date_chunks(): void {
+		$og = $this->renderer()->compose_og( $this->fixture_bytes(), 'Short caption' );
+
+		$this->assertFalse( strpos( $og['bytes'], 'date:create' ), 'PNG must not embed a date:create text chunk' );
+		$this->assertFalse( strpos( $og['bytes'], 'date:modify' ), 'PNG must not embed a date:modify text chunk' );
+		$this->assertFalse( strpos( $og['bytes'], 'tIME' ), 'PNG must not embed a tIME chunk' );
+	}
+}

tests/unit/Core/ImageComposerLayoutTest.php

@@ -0,0 +1,144 @@
+<?php
+/**
+ * Tests for PRAutoBlogger_Image_Composer_Layout.
+ *
+ * Validates the caption clamp (word wrap, hard budgets, ellipsis, multibyte)
+ * and the shape of the layout defaults consumed by the renderers.
+ *
+ * @package PRAutoBlogger\Tests\Core
+ */
+
+namespace PRAutoBlogger\Tests\Core;
+
+use PRAutoBlogger\Tests\BaseTestCase;
+
+class ImageComposerLayoutTest extends BaseTestCase {
+
+	/**
+	 * Empty and whitespace-only captions clamp to no lines at all.
+	 */
+	public function test_empty_caption_returns_no_lines(): void {
+		$this->assertSame( [], \PRAutoBlogger_Image_Composer_Layout::clamp_caption( '', 52, 2 ) );
+		$this->assertSame( [], \PRAutoBlogger_Image_Composer_Layout::clamp_caption( "  \n\t ", 52, 2 ) );
+	}
+
+	/**
+	 * A single short word stays on one line, untouched.
+	 */
+	public function test_single_word_caption(): void {
+		$this->assertSame(
+			[ 'Collagen' ],
+			\PRAutoBlogger_Image_Composer_Layout::clamp_caption( 'Collagen', 52, 2 )
+		);
+	}
+
+	/**
+	 * A caption exactly at the per-line budget fills the line with no
+	 * ellipsis and no spill.
+	 */
+	public function test_caption_exactly_at_budget_is_not_truncated(): void {
+		$caption = 'abcde fghij'; // 11 chars, budget 11.
+		$lines   = \PRAutoBlogger_Image_Composer_Layout::clamp_caption( $caption, 11, 1 );
+
+		$this->assertSame( [ 'abcde fghij' ], $lines );
+	}
+
+	/**
+	 * A caption exactly filling max_lines is kept in full (boundary: the
+	 * ellipsis only appears when content is actually dropped).
+	 */
+	public function test_caption_exactly_filling_max_lines_keeps_all_words(): void {
+		$lines = \PRAutoBlogger_Image_Composer_Layout::clamp_caption( 'aa bb cc dd', 5, 2 );
+
+		$this->assertSame( [ 'aa bb', 'cc dd' ], $lines );
+	}
+
+	/**
+	 * 3× the budget gets cut at max_lines with a trailing ellipsis, and no
+	 * line ever exceeds the per-line budget.
+	 */
+	public function test_overflowing_caption_is_ellipsized_within_budget(): void {
+		$caption = 'Collagen fragments may aid joint repair according to early trials in athletes';
+		$lines   = \PRAutoBlogger_Image_Composer_Layout::clamp_caption( $caption, 20, 2 );
+
+		$this->assertCount( 2, $lines );
+		$this->assertStringEndsWith( \PRAutoBlogger_Image_Composer_Layout::ELLIPSIS, $lines[1] );
+		foreach ( $lines as $line ) {
+			$this->assertLessThanOrEqual( 20, mb_strlen( $line ) );
+		}
+	}
+
+	/**
+	 * Words wrap at word boundaries — a word never straddles two lines when
+	 * it fits on the next one.
+	 */
+	public function test_wraps_at_word_boundaries(): void {
+		$lines = \PRAutoBlogger_Image_Composer_Layout::clamp_caption( 'peptide bonds form chains', 13, 3 );
+
+		$this->assertSame( [ 'peptide bonds', 'form chains' ], $lines );
+	}
+
+	/**
+	 * A single word longer than a full line is hard-split instead of
+	 * overflowing the canvas.
+	 */
+	public function test_overlong_single_word_is_hard_split(): void {
+		$lines = \PRAutoBlogger_Image_Composer_Layout::clamp_caption( 'abcdefghij', 4, 3 );
+
+		$this->assertSame( [ 'abcd', 'efgh', 'ij' ], $lines );
+	}
+
+	/**
+	 * Multibyte captions are measured in characters, not bytes, and the
+	 * ellipsis path keeps each line within the budget.
+	 */
+	public function test_multibyte_caption_counts_characters_not_bytes(): void {
+		$lines = \PRAutoBlogger_Image_Composer_Layout::clamp_caption( 'ペプチドは結合組織を強化する可能性がある', 6, 2 );
+
+		$this->assertCount( 2, $lines );
+		foreach ( $lines as $line ) {
+			$this->assertLessThanOrEqual( 6, mb_strlen( $line ) );
+		}
+		$this->assertStringEndsWith( \PRAutoBlogger_Image_Composer_Layout::ELLIPSIS, $lines[1] );
+	}
+
+	/**
+	 * Interior whitespace runs (newlines, tabs, doubles) collapse to single
+	 * spaces before wrapping.
+	 */
+	public function test_whitespace_is_collapsed_before_wrapping(): void {
+		$lines = \PRAutoBlogger_Image_Composer_Layout::clamp_caption( "joint \n\t repair", 20, 2 );
+
+		$this->assertSame( [ 'joint repair' ], $lines );
+	}
+
+	/**
+	 * Layout defaults carry every key the renderers consume, with the
+	 * spec'd headline geometry (band 120, square slice 569, footer 96).
+	 */
+	public function test_defaults_shape_matches_renderer_contract(): void {
+		$defaults = \PRAutoBlogger_Image_Composer_Layout::defaults();
+
+		$this->assertSame( [ 'featured', 'og', 'square' ], array_keys( $defaults ) );
+
+		$this->assertSame( 28, $defaults['featured']['mark_height'] );
+		$this->assertSame( 0.55, $defaults['featured']['mark_opacity'] );
+
+		$this->assertSame( 1200, $defaults['og']['width'] );
+		$this->assertSame( 630, $defaults['og']['height'] );
+		$this->assertSame( 120, $defaults['og']['band_height'] );
+		$this->assertSame( 2, $defaults['og']['caption_max_lines'] );
+
+		$this->assertSame( 1080, $defaults['square']['width'] );
+		$this->assertSame( 1080, $defaults['square']['height'] );
+		$this->assertSame( 569, $defaults['square']['slice_height'] );
+		$this->assertSame( 96, $defaults['square']['footer_height'] );
+		$this->assertSame( 3, $defaults['square']['caption_max_lines'] );
+
+		foreach ( [ 'og', 'square' ] as $role ) {
+			foreach ( [ 'caption_font', 'caption_size', 'caption_color', 'caption_chars_per_line', 'caption_line_height' ] as $key ) {
+				$this->assertArrayHasKey( $key, $defaults[ $role ], "$role missing $key" );
+			}
+		}
+	}
+}

tests/unit/Core/ImageComposerTest.php

@@ -0,0 +1,325 @@
+<?php
+/**
+ * Tests for PRAutoBlogger_Image_Composer (orchestrator).
+ *
+ * Validates the degradation ladder (Imagick mocked present/absent via the
+ * capability filter), pass-through guarantees, variant config whitelisting,
+ * capability caching, and the uninstall prefix contract.
+ *
+ * @package PRAutoBlogger\Tests\Core
+ */
+
+namespace PRAutoBlogger\Tests\Core;
+
+use PRAutoBlogger\Tests\BaseTestCase;
+use Brain\Monkey\Functions;
+use Brain\Monkey\Filters;
+
+class ImageComposerTest extends BaseTestCase {
+
+	/** @var array Default provider-result fixture fed into compose(). */
+	private array $image_data = [
+		'bytes'      => 'raw_base_bytes',
+		'mime_type'  => 'image/png',
+		'width'      => 1200,
+		'height'     => 632,
+		'model'      => 'flux-1-schnell',
+		'cost_usd'   => 0.0006,
+		'latency_ms' => 1500,
+	];
+
+	protected function setUp(): void {
+		parent::setUp();
+		\PRAutoBlogger_Image_Composer::reset_run_state();
+		Functions\when( 'update_option' )->justReturn( true );
+		$this->stub_get_option( [] ); // All composer options fall back to defaults.
+	}
+
+	protected function tearDown(): void {
+		\PRAutoBlogger_Image_Composer::reset_run_state();
+		parent::tearDown();
+	}
+
+	/** Helper: composer context for Image A. */
+	private function context( string $slot = 'image_a' ): array {
+		return [
+			'post_id' => 7,
+			'caption' => 'Collagen fragments may aid joint repair',
+			'title'   => 'Collagen Peptides Explained',
+			'slot'    => $slot,
+		];
+	}
+
+	/** Helper: a fake rendered variant payload. */
+	private function variant( string $role, int $w, int $h ): array {
+		return [
+			'bytes'     => "rendered_{$role}",
+			'mime_type' => 'image/png',
+			'width'     => $w,
+			'height'    => $h,
+			'role'      => $role,
+		];
+	}
+
+	/**
+	 * Compose disabled in settings → single pass-through featured variant,
+	 * renderer untouched.
+	 */
+	public function test_disabled_setting_returns_passthrough_only(): void {
+		$this->stub_get_option( [ \PRAutoBlogger_Image_Composer::OPTION_ENABLED => '0' ] );
+
+		$renderer = $this->createMock( \PRAutoBlogger_Image_Composer_Imagick::class );
+		$renderer->expects( $this->never() )->method( 'compose_featured' );
+		$renderer->expects( $this->never() )->method( 'compose_og' );
+
+		$composer = new \PRAutoBlogger_Image_Composer( $renderer );
+		$variants = $composer->compose( $this->image_data, $this->context() );
+
+		$this->assertCount( 1, $variants );
+		$this->assertSame( 'featured', $variants[0]['role'] );
+		$this->assertSame( 'raw_base_bytes', $variants[0]['bytes'] );
+	}
+
+	/**
+	 * Empty provider bytes short-circuit to pass-through (no probe, no render).
+	 */
+	public function test_empty_bytes_return_passthrough(): void {
+		$composer = new \PRAutoBlogger_Image_Composer(
+			$this->createMock( \PRAutoBlogger_Image_Composer_Imagick::class )
+		);
+		$variants = $composer->compose( [ 'bytes' => '' ], $this->context() );
+
+		$this->assertCount( 1, $variants );
+		$this->assertSame( 'featured', $variants[0]['role'] );
+	}
+
+	/**
+	 * Ladder rung 1 (Imagick "present" via filter + mocked renderer):
+	 * Image A yields marked featured + og + square, featured first, with the
+	 * caption forwarded to both text-bearing variants.
+	 */
+	public function test_imagick_rung_renders_featured_plus_variants(): void {
+		Filters\expectApplied( 'prautoblogger_image_compose_capability' )->andReturn( 'imagick' );
+
+		$caption  = $this->context()['caption'];
+		$renderer = $this->createMock( \PRAutoBlogger_Image_Composer_Imagick::class );
+		$renderer->expects( $this->once() )->method( 'compose_featured' )
+			->with( 'raw_base_bytes' )->willReturn( $this->variant( 'featured', 1200, 632 ) );
+		$renderer->expects( $this->once() )->method( 'compose_og' )
+			->with( 'raw_base_bytes', $caption )->willReturn( $this->variant( 'og', 1200, 630 ) );
+		$renderer->expects( $this->once() )->method( 'compose_square' )
+			->with( 'raw_base_bytes', $caption )->willReturn( $this->variant( 'square', 1080, 1080 ) );
+
+		$composer = new \PRAutoBlogger_Image_Composer( $renderer );
+		$variants = $composer->compose( $this->image_data, $this->context() );
+
+		$this->assertSame( [ 'featured', 'og', 'square' ], array_column( $variants, 'role' ) );
+		$this->assertSame( 'rendered_featured', $variants[0]['bytes'] );
+	}
+
+	/**
+	 * Featured corner mark toggled off → featured stays the untouched base,
+	 * but social variants still render.
+	 */
+	public function test_mark_disabled_passes_featured_through_but_keeps_variants(): void {
+		Filters\expectApplied( 'prautoblogger_image_compose_capability' )->andReturn( 'imagick' );
+		$this->stub_get_option( [ \PRAutoBlogger_Image_Composer::OPTION_MARK_ENABLED => '0' ] );
+
+		$renderer = $this->createMock( \PRAutoBlogger_Image_Composer_Imagick::class );
+		$renderer->expects( $this->never() )->method( 'compose_featured' );
+		$renderer->method( 'compose_og' )->willReturn( $this->variant( 'og', 1200, 630 ) );
+		$renderer->method( 'compose_square' )->willReturn( $this->variant( 'square', 1080, 1080 ) );
+
+		$composer = new \PRAutoBlogger_Image_Composer( $renderer );
+		$variants = $composer->compose( $this->image_data, $this->context() );
+
+		$this->assertSame( 'raw_base_bytes', $variants[0]['bytes'] );
+		$this->assertSame( [ 'featured', 'og', 'square' ], array_column( $variants, 'role' ) );
+	}
+
+	/**
+	 * Image B slot gets the corner mark only — no og/square renders ever.
+	 */
+	public function test_image_b_slot_yields_mark_only(): void {
+		Filters\expectApplied( 'prautoblogger_image_compose_capability' )->andReturn( 'imagick' );
+
+		$renderer = $this->createMock( \PRAutoBlogger_Image_Composer_Imagick::class );
+		$renderer->expects( $this->once() )->method( 'compose_featured' )
+			->willReturn( $this->variant( 'featured', 1200, 632 ) );
+		$renderer->expects( $this->never() )->method( 'compose_og' );
+		$renderer->expects( $this->never() )->method( 'compose_square' );
+
+		$composer = new \PRAutoBlogger_Image_Composer( $renderer );
+		$variants = $composer->compose( $this->image_data, $this->context( 'image_b' ) );
+
+		$this->assertCount( 1, $variants );
+		$this->assertSame( 'featured', $variants[0]['role'] );
+	}
+
+	/**
+	 * The variant option is whitelisted at point of use: unknown tokens are
+	 * dropped, duplicates deduped, config order preserved.
+	 */
+	public function test_variant_config_is_whitelisted_and_ordered(): void {
+		Filters\expectApplied( 'prautoblogger_image_compose_capability' )->andReturn( 'imagick' );
+		$this->stub_get_option(
+			[ \PRAutoBlogger_Image_Composer::OPTION_VARIANTS => ' square, banana ,og, og' ]
+		);
+
+		$renderer = $this->createMock( \PRAutoBlogger_Image_Composer_Imagick::class );
+		$renderer->method( 'compose_featured' )->willReturn( $this->variant( 'featured', 1200, 632 ) );
+		$renderer->expects( $this->once() )->method( 'compose_square' )
+			->willReturn( $this->variant( 'square', 1080, 1080 ) );
+		$renderer->expects( $this->once() )->method( 'compose_og' )
+			->willReturn( $this->variant( 'og', 1200, 630 ) );
+
+		$composer = new \PRAutoBlogger_Image_Composer( $renderer );
+		$variants = $composer->compose( $this->image_data, $this->context() );
+
+		$this->assertSame( [ 'featured', 'square', 'og' ], array_column( $variants, 'role' ) );
+	}
+
+	/**
+	 * Acceptance: with every render throwing (e.g. probe lied / Imagick
+	 * flipped mid-run), compose() still returns the publishable pass-through
+	 * featured variant and never lets the exception escape.
+	 */
+	public function test_renderer_failure_degrades_to_passthrough(): void {
+		Filters\expectApplied( 'prautoblogger_image_compose_capability' )->andReturn( 'imagick' );
+
+		$renderer = $this->createMock( \PRAutoBlogger_Image_Composer_Imagick::class );
+		$renderer->method( 'compose_featured' )->willThrowException( new \RuntimeException( 'no imagick after all' ) );
+		$renderer->method( 'compose_og' )->willThrowException( new \RuntimeException( 'no imagick after all' ) );
+		$renderer->method( 'compose_square' )->willThrowException( new \RuntimeException( 'no imagick after all' ) );
+
+		$composer = new \PRAutoBlogger_Image_Composer( $renderer );
+		$variants = $composer->compose( $this->image_data, $this->context() );
+
+		$this->assertCount( 1, $variants );
+		$this->assertSame( 'featured', $variants[0]['role'] );
+		$this->assertSame( 'raw_base_bytes', $variants[0]['bytes'] );
+	}
+
+	/**
+	 * Ladder rung 3 forced via the override filter: pass-through, no renderer
+	 * involvement, publish data intact.
+	 */
+	public function test_capability_none_passes_through(): void {
+		Filters\expectApplied( 'prautoblogger_image_compose_capability' )->andReturn( 'none' );
+
+		$renderer = $this->createMock( \PRAutoBlogger_Image_Composer_Imagick::class );
+		$renderer->expects( $this->never() )->method( 'compose_featured' );
+
+		$composer = new \PRAutoBlogger_Image_Composer( $renderer );
+		$variants = $composer->compose( $this->image_data, $this->context() );
+
+		$this->assertCount( 1, $variants );
+		$this->assertSame( 'raw_base_bytes', $variants[0]['bytes'] );
+		$this->assertSame( 1200, $variants[0]['width'] );
+		$this->assertSame( 632, $variants[0]['height'] );
+	}
+
+	/**
+	 * A garbage filter return is coerced to 'none' (pass-through), never an
+	 * undefined rung.
+	 */
+	public function test_unknown_capability_value_is_treated_as_none(): void {
+		Filters\expectApplied( 'prautoblogger_image_compose_capability' )->andReturn( 'webgpu' );
+
+		$composer = new \PRAutoBlogger_Image_Composer(
+			$this->createMock( \PRAutoBlogger_Image_Composer_Imagick::class )
+		);
+		$variants = $composer->compose( $this->image_data, $this->context() );
+
+		$this->assertCount( 1, $variants );
+		$this->assertSame( 'featured', $variants[0]['role'] );
+	}
+
+	/**
+	 * A cached probe with a matching environment fingerprint is reused —
+	 * no re-probe, no option write. (update_option calls are captured via a
+	 * when() alias: an expect() here would be shadowed by the setUp stub.)
+	 */
+	public function test_matching_capability_cache_skips_probe_write(): void {
+		$fingerprint = md5(
+			PHP_VERSION . '|' . ( extension_loaded( 'imagick' ) ? 'im1' : 'im0' ) . '|' . ( extension_loaded( 'gd' ) ? 'gd1' : 'gd0' )
+		);
+		$this->stub_get_option(
+			[
+				\PRAutoBlogger_Image_Composer::OPTION_CAPABILITY => [
+					'fingerprint' => $fingerprint,
+					'capability'  => 'none',
+				],
+			]
+		);
+		$writes = [];
+		Functions\when( 'update_option' )->alias(
+			function ( $key, $value = null, $autoload = null ) use ( &$writes ) {
+				$writes[] = $key;
+				return true;
+			}
+		);
+
+		$composer = new \PRAutoBlogger_Image_Composer(
+			$this->createMock( \PRAutoBlogger_Image_Composer_Imagick::class )
+		);
+		$variants = $composer->compose( $this->image_data, $this->context() );
+
+		$this->assertSame( 'featured', $variants[0]['role'] );
+		$this->assertSame( [], $writes, 'A matching cache fingerprint must not trigger a probe rewrite.' );
+	}
+
+	/**
+	 * A stale fingerprint (host changed) triggers a fresh probe and a cache
+	 * rewrite — the auto-invalidation the spec requires. (Captured via a
+	 * when() alias: an expect() here would be shadowed by the setUp stub.)
+	 */
+	public function test_stale_capability_cache_reprobes_and_rewrites(): void {
+		$this->stub_get_option(
+			[
+				\PRAutoBlogger_Image_Composer::OPTION_CAPABILITY => [
+					'fingerprint' => 'old-host-fingerprint',
+					'capability'  => 'imagick',
+				],
+			]
+		);
+		$writes = [];
+		Functions\when( 'update_option' )->alias(
+			function ( $key, $value = null, $autoload = null ) use ( &$writes ) {
+				$writes[] = [ $key, $value, $autoload ];
+				return true;
+			}
+		);
+
+		$composer = new \PRAutoBlogger_Image_Composer(
+			$this->createMock( \PRAutoBlogger_Image_Composer_Imagick::class )
+		);
+		$variants = $composer->compose( $this->image_data, $this->context() );
+
+		$this->assertSame( 'featured', $variants[0]['role'] );
+		$this->assertCount( 1, $writes, 'A stale fingerprint must rewrite the capability cache.' );
+		$this->assertSame( \PRAutoBlogger_Image_Composer::OPTION_CAPABILITY, $writes[0][0] );
+		$this->assertIsArray( $writes[0][1] );
+		$this->assertArrayHasKey( 'capability', $writes[0][1] );
+		$this->assertNotSame( 'old-host-fingerprint', $writes[0][1]['fingerprint'] ?? '' );
+		$this->assertFalse( $writes[0][2], 'Capability cache must not autoload.' );
+	}
+
+	/**
+	 * QA note for the uninstall contract: every new option key keeps the
+	 * `prautoblogger_` prefix so uninstall.php's prefix-sweep purges it.
+	 * (Per spec, uninstall.php itself is intentionally untouched.)
+	 */
+	public function test_new_option_keys_keep_uninstall_sweep_prefix(): void {
+		$keys = [
+			\PRAutoBlogger_Image_Composer::OPTION_ENABLED,
+			\PRAutoBlogger_Image_Composer::OPTION_VARIANTS,
+			\PRAutoBlogger_Image_Composer::OPTION_MARK_ENABLED,
+			\PRAutoBlogger_Image_Composer::OPTION_CAPABILITY,
+		];
+
+		foreach ( $keys as $key ) {
+			$this->assertStringStartsWith( 'prautoblogger_', $key );
+		}
+	}
+}

tests/unit/Core/ImagePipelineTest.php

@@ -18,6 +18,11 @@ class ImagePipelineTest extends BaseTestCase {
 	protected function setUp(): void {
 		parent::setUp();
 
+		// v0.17.0: the composer caches its capability probe via update_option
+		// and keeps a once-per-run warning flag that must not leak between tests.
+		\PRAutoBlogger_Image_Composer::reset_run_state();
+		Functions\when( 'update_option' )->justReturn( true );
+
 		// Mock WordPress functions used by the pipeline and its dependencies.
 		Functions\when( 'is_wp_error' )->alias( function ( $thing ) {
 			return $thing instanceof \WP_Error;
@@ -346,6 +351,67 @@ class ImagePipelineTest extends BaseTestCase {
 		$this->assertNotEmpty( $result['errors'] );
 	}
 
+	/**
+	 * v0.17.0: composed OG/square variants are sideloaded and meta-linked —
+	 * role + base-attachment meta on the variant attachments, role-specific
+	 * image ID meta on the post, and the featured attachment tagged with its
+	 * role. Composition adds no cost-tracker rows beyond the primary image.
+	 */
+	public function test_composed_variants_are_sideloaded_and_meta_linked(): void {
+		$image_result = [
+			'bytes'      => 'fake_image_data',
+			'mime_type'  => 'image/png',
+			'width'      => 1200,
+			'height'     => 632,
+			'model'      => 'test-model',
+			'cost_usd'   => 0.05,
+			'latency_ms' => 2000,
+		];
+
+		$provider = $this->createMock( \PRAutoBlogger_Image_Provider_Interface::class );
+		$provider->method( 'estimate_cost' )->willReturn( 0.05 );
+		$provider->method( 'generate_image_batch' )->willReturn( [ 'image_a' => $image_result ] );
+
+		$cost_tracker = $this->createMock( \PRAutoBlogger_Cost_Tracker::class );
+		$cost_tracker->method( 'would_exceed_budget' )->willReturn( false );
+		// Exactly one cost row: the primary image. Variants are $0 local renders.
+		$cost_tracker->expects( $this->exactly( 1 ) )->method( 'log_image_generation' );
+
+		$composer = new class() implements \PRAutoBlogger_Image_Composer_Interface {
+			public function compose( array $image_data, array $context ): array {
+				return [
+					[ 'bytes' => 'marked', 'mime_type' => 'image/png', 'width' => 1200, 'height' => 632, 'role' => 'featured' ],
+					[ 'bytes' => 'og_png', 'mime_type' => 'image/png', 'width' => 1200, 'height' => 630, 'role' => 'og' ],
+					[ 'bytes' => 'sq_png', 'mime_type' => 'image/png', 'width' => 1080, 'height' => 1080, 'role' => 'square' ],
+				];
+			}
+		};
+
+		Functions\when( 'get_temp_dir' )->justReturn( '/tmp/' );
+		$next_id = 41;
+		Functions\when( 'media_handle_sideload' )->alias( function () use ( &$next_id ) {
+			return ++$next_id; // 42 featured, 43 og, 44 square.
+		} );
+
+		$meta_calls = [];
+		Functions\when( 'update_post_meta' )->alias( function ( $object_id, $key, $value ) use ( &$meta_calls ) {
+			$meta_calls[] = [ $object_id, $key, $value ];
+			return true;
+		} );
+
+		$pipeline = new \PRAutoBlogger_Image_Pipeline( $provider, $cost_tracker, null, $composer );
+		$result   = $pipeline->generate_and_attach_images( 1, [ 'post_title' => 'Test' ], null );
+
+		$this->assertSame( 42, $result['image_a_id'] );
+		$this->assertContains( [ 42, '_prautoblogger_image_role', 'featured' ], $meta_calls );
+		$this->assertContains( [ 43, '_prautoblogger_image_role', 'og' ], $meta_calls );
+		$this->assertContains( [ 43, '_prautoblogger_base_attachment_id', 42 ], $meta_calls );
+		$this->assertContains( [ 1, '_prautoblogger_og_image_id', 43 ], $meta_calls );
+		$this->assertContains( [ 44, '_prautoblogger_image_role', 'square' ], $meta_calls );
+		$this->assertContains( [ 44, '_prautoblogger_base_attachment_id', 42 ], $meta_calls );
+		$this->assertContains( [ 1, '_prautoblogger_square_image_id', 44 ], $meta_calls );
+	}
+
 	/**
 	 * Test graceful handling when one image in the batch returns an error.
 	 */

tests/unit/Core/ImagePromptBuilderTest.php

@@ -3,7 +3,7 @@
  * Tests for PRAutoBlogger_Image_Prompt_Builder.
  *
  * Validates prompt generation from article content and source data,
- * including style suffix appending and HTML stripping.
+ * including editorial-template substitution ({{ topic_summary }}) and HTML stripping.
  *
  * @package PRAutoBlogger\Tests\Core
  */
@@ -68,7 +68,9 @@ class ImagePromptBuilderTest extends BaseTestCase {
 		[ 'prompt' => $scene, 'caption' => $caption ] = $builder->build_article_prompt( $article_data );
 
 		$this->assertStringContainsString( 'How to Train Your Dragon', $scene );
-		// Style suffix should be appended.
+		// Editorial template wraps the topic summary; token must be substituted.
+		$this->assertStringNotContainsString( '{{ topic_summary }}', $scene );
+		$this->assertStringContainsString( 'Editorial scientific illustration', $scene );
 		$this->assertNotEmpty( $scene );
 		$this->assertGreaterThan( 50, strlen( $scene ) );
 		$this->assertIsString( $caption );