feat(phase2b): P2b.4 — tier routing + Authority pipeline + citation/imagery gates (#181, v0.31.0)

Authority_Pipeline orchestrator (research→curate→draft→editorial→seo→publish gate) + per-category tier router behind master flag prautoblogger_authority_pipeline_enabled (DEFAULT OFF — zero behavior change until enabled). Cost-ceiling halts→hold; citation + imagery gates. QA APPROVE b086079; CI green (phpcs+phpunit VPS-verified).

Agent-Session: prab-phase2b-4-merge

ARCHITECTURE.md

@@ -229,6 +229,9 @@ prautoblogger/
 │   │   ├── class-editorial-loop.php    # P2b.2: bounded editorial loop — editor↔writer ≤editorial_max_rounds — Authority only (v0.29.0)
 │   │   ├── class-editorial-revision-caller.php # P2b.2: writer revision LLM step (extracted from editorial-loop for 300-line rule) (v0.29.0)
 │   │   ├── class-seo-stage.php         # P2b.3: SEO stage — writes _prab_* post-meta (JSON-LD contract) + computes citation_score — Authority only (v0.30.0)
+											# P2b.4: class-authority-pipeline.php  Authority pipeline orchestrator 6-stage (v0.31.0)
+											# P2b.4: class-authority-pipeline-stages.php stage helpers (v0.31.0)
+											# P2b.4: class-tier-router.php per-category tier router (v0.31.0)
 │   │   ├── class-audit-writer.php     # run_sources / run_decisions insert layer
 │   │   ├── class-pipeline-status.php  # Status-transient + summary helpers (extracted from runner/worker)
 │   │   ├── class-logger.php           # Structured logging singleton (error/warning/info/debug)
@@ -250,6 +253,8 @@ prautoblogger/
 │   │   ├── interface-research-judge.php    # P2b.1: contract for the curate stage judge (v0.28.0)
 │   │   ├── interface-editorial-loop.php    # P2b.2: contract for bounded editorial loop (v0.29.0)
 │   │   ├── interface-seo-stage.php         # P2b.3: contract for the SEO stage (v0.30.0)
+											# P2b.4: interface-tier-router.php contract for tier router (v0.31.0)
+											# P2b.4: interface-authority-pipeline.php contract for Authority pipeline (v0.31.0)
 │   │   ├── class-reddit-provider.php     # Reddit data collection orchestrator (RSS primary)
 │   │   ├── interface-image-provider.php  # Contract for any image generation provider (incl. batch)
 │   │   ├── class-open-router-image-provider.php  # OpenRouter image gen (single + batch dispatch)
@@ -696,6 +701,8 @@ All prefixed with `prautoblogger_`:
 | `prautoblogger_board_published_window_days` | Days back to show in the Published column (default 7). |
 | `prautoblogger_editorial_max_rounds`    | Authority-tier editorial loop: max editor↔writer rounds before Review Queue escalation (int, default 3, range 1–10). P2b.2 (v0.29.0). |
 | `prautoblogger_citation_score_threshold` | Authority-tier SEO stage: minimum citation_score to pass the publish gate (float, default 0.0 — intentionally uncalibrated; calibrate after first ~10 Authority runs). P2b.3 (v0.30.0). |
+| `prautoblogger_authority_pipeline_enabled` | Master switch for Authority-tier pipeline (bool, default false). OFF = all generation uses Economy path (zero behaviour change). P2b.4 v0.31.0. |
+| `prautoblogger_category_tiers` | Per-category tier overrides: serialized array [category_slug => economy]. Economy is an explicit demote; default is Authority. P2b.4 v0.31.0. |
 
 ### Post Meta
 
@@ -723,6 +730,7 @@ Stored on every PRAutoBlogger-generated post:
 | `_prab_review_mode`                  | `editorial-system` (automated SEO stage) or `human` (set in P2b.4 on Review Queue approval). |
 | `_prab_reviewed_at`                  | ISO 8601 datetime of when the SEO stage ran (P2b.3 v0.30.0). |
 | `_prab_citation_score`               | Float (stored as string): average quality_score of kept sources. Publish gate in P2b.4. |
+| `_prautoblogger_imagery_suppressed`   | Set to 1 on articles held by citation gate or editorial escalation (P2b.4 v0.31.0). Suppresses image generation until human-approved. |
 
 Composed-variant **attachment** meta (v0.17.0): every pipeline attachment gets
 `_prautoblogger_image_role` (`featured`/`og`/`square`); OG/square variants also

CHANGELOG.md

@@ -5,6 +5,27 @@ 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/).
 
+## [0.31.0] - 2026-06-24
+
+### Added
+- **P2b.4 — tier routing + Authority pipeline orchestrator + citation/imagery gates**
+  - `PRAutoBlogger_Tier_Router` (`core/class-tier-router.php`, 100 lines): resolves Authority vs Economy per-category. Master switch `prautoblogger_authority_pipeline_enabled` defaults FALSE — flag OFF means ALL generation uses the Economy single-pass path, byte-identical to pre-P2b.4.
+  - `PRAutoBlogger_Tier_Router_Interface` (`providers/interface-tier-router.php`).
+  - `PRAutoBlogger_Authority_Pipeline` (`core/class-authority-pipeline.php`, 247 lines): 6-stage orchestrator: research -> curate -> draft -> editorial -> seo -> publish gate. Cost-governor reserve/settle on every stage; `PRAutoBlogger_Cost_Ceiling_Exception` -> HOLD as draft (never force-complete). Citation gate: `citation_score >= threshold` to publish (default threshold 0.0, gate always passes until calibrated).
+  - `PRAutoBlogger_Authority_Pipeline_Stages` (`core/class-authority-pipeline-stages.php`, 195 lines): stage helpers extracted for 300-line rule.
+  - `PRAutoBlogger_Authority_Pipeline_Interface` (`providers/interface-authority-pipeline.php`).
+  - **Article_Worker wired**: 3-line tier check before Economy path. Economy path unchanged.
+  - **Imagery gate**: held articles get `_prautoblogger_imagery_suppressed = 1`; image pipeline skipped. Published articles proceed normally.
+  - New options: `prautoblogger_authority_pipeline_enabled` (bool, default false), `prautoblogger_category_tiers` (serialized array, default empty = all Authority).
+- PHPUnit: `TierRouterTest` (6 tests) + `AuthorityPipelineTest` (6 tests). All 544 tests GREEN on VPS PHP 8.3.
+
+### Updated
+- `ARCHITECTURE.md` — new files, options, post-meta, generation flow note (additions only).
+- `CONVENTIONS.md` — tier routing + master flag pattern.
+- `CONTEXT.md` — P2b.4 glossary section.
+- `prautoblogger.php` — version bumped to 0.31.0.
+- `uninstall.php` — new options covered by existing wildcard; `_prab_*` purge already present.
+
 ## [0.30.0] - 2026-06-24
 
 ### Fixed (QA P1/P2 sweep — post-a39fb75)

CONTEXT.md

@@ -210,3 +210,15 @@ into the live Economy path until P2b.4).
 | **_prab_reviewed_by** | WP user ID of the Review Queue approver. **NOT written by P2b.3**. Set exclusively by P2b.4 on human approval. |
 | **_prab_citations** | JSON-encoded array of kept research sources: `[{url, title, doi?, quality_score?}]`. Derived from the `$kept_sources` array passed by the curate stage. |
 | **_prab_about_peptides** | JSON-encoded array of related peptide post IDs. Populated from P2b.4 peptide linkage; defaults to `[]` in P2b.3 (the SEO stage accepts the array as a parameter for future-compatibility). |
+
+## P2b.4 Glossary (Tier Router + Authority Pipeline Orchestrator)
+
+| Term | Definition |
+|------|-----------|
+| **Tier routing** | The process of routing an article idea to Authority or Economy (single-pass) path. Implemented in `PRAutoBlogger_Tier_Router::resolve()`. |
+| **Master flag** | `prautoblogger_authority_pipeline_enabled` (default `false`). When OFF, ALL generation uses Economy path — zero behaviour change from pre-P2b.4. Must be explicitly enabled by an operator. |
+| **Category tier map** | `prautoblogger_category_tiers` — serialized array `[category_slug => economy]`. Only `economy` is a meaningful explicit demote; unclassified categories default to Authority. |
+| **Authority Pipeline** | `PRAutoBlogger_Authority_Pipeline` — 6-stage orchestrator: research -> curate -> draft -> editorial -> seo -> publish gate. Wires together P2b.1+P2b.2+P2b.3 subsystems. |
+| **Citation gate** | Publish gate in the Authority pipeline: `citation_score >= threshold` to publish; else hold as draft with imagery suppressed. Default threshold `0.0` (gate always passes until calibrated). |
+| **Imagery gate** | `_prautoblogger_imagery_suppressed = 1` written on held articles. Signals image pipeline to skip generation. Not set on published articles. |
+| **Cost ceiling halt** | `PRAutoBlogger_Cost_Ceiling_Exception` caught at Authority pipeline top level. Article saved as draft with status `halted`; never force-completed. |

CONVENTIONS.md

@@ -828,3 +828,37 @@ post-meta writes and DB audit rows. It is the contract point between PRAB (write
 | `_prab_reviewed_at` | string | ISO 8601 datetime |
 | `_prab_reviewed_by` | int | WP user ID — written only by P2b.4 on human approval |
 | `_prab_citation_score` | string (float) | Avg quality_score of kept sources; publish gate in P2b.4 |
+
+---
+
+## Tier Routing + Master Flag Pattern (P2b.4, v0.31.0)
+
+### Design rules
+
+The master flag `prautoblogger_authority_pipeline_enabled` (default `false`) gates
+the entire Authority pipeline. When OFF, `PRAutoBlogger_Tier_Router::resolve()` MUST
+return `economy` unconditionally — no category-map reads, no secondary checks. This
+guarantees zero behaviour change in production on deploy.
+
+### Key patterns
+
+- **Master flag check first**: always the first branch in `resolve()`. If false, return
+  economy immediately without reading the category map.
+- **Economy is the safe default**: if the category map is empty, absent, or corrupt,
+  the tier defaults to authority (the additive default when flag is ON); but the flag
+  being OFF is the primary safety gate.
+- **Per-category demotion**: the `prautoblogger_category_tiers` option stores a
+  serialized PHP array `[category_slug => economy]`. Only economy is a meaningful
+  explicit value — other values fall through to the Authority default.
+- **Article_Worker integration**: three-line check before the Economy path:
+  ```php
+  $tier = ( new PRAutoBlogger_Tier_Router() )->resolve( $idea );
+  if ( authority === $tier ) {
+      return ( new PRAutoBlogger_Authority_Pipeline( $cost_tracker ) )->run( $run_id, $idea, $cost_tracker );
+  }
+  ```
+  The Economy path below the check is UNCHANGED — the branch is additive-only.
+- **Imagery gate**: held articles (citation gate miss, escalation, or cost ceiling) get
+  `_prautoblogger_imagery_suppressed = 1` post-meta. Image pipeline checks this key
+  before running. Publish-gate-passed articles never have this key set.
+

includes/core/class-article-worker.php

@@ -83,6 +83,14 @@ class PRAutoBlogger_Article_Worker {
 			return $result;
 		}
 
+		// P2b.4: tier routing — flag OFF always returns 'economy' (zero behaviour change).
+		$tier = ( new PRAutoBlogger_Tier_Router() )->resolve( $idea );
+		if ( 'authority' === $tier ) {
+			$pipeline = new PRAutoBlogger_Authority_Pipeline( $this->cost_tracker );
+			return $pipeline->run( $run_id, $idea, $this->cost_tracker );
+		}
+		// Economy path continues unchanged below...
+
 		// Initialize Opik trace context for this article generation.
 		$opik = $this->should_trace_with_opik();
 		if ( $opik ) {

includes/core/class-authority-pipeline-stages.php

@@ -0,0 +1,197 @@
+<?php
+declare(strict_types=1);
+
+/**
+ * phpcs:ignore WordPress.Files.FileName.InvalidClassFileName -- class naming convention differs from WordPress standard
+ *
+ * Stage execution helpers for the Authority pipeline orchestrator.
+ *
+ * What: Extracted from PRAutoBlogger_Authority_Pipeline to keep the
+ *       orchestrator under 300 lines. Contains per-stage call wrappers,
+ *       the imagery gate, and the hold-article helper. No external I/O
+ *       beyond what the individual stage classes already require.
+ *
+ * Who triggers it: PRAutoBlogger_Authority_Pipeline (P2b.4).
+ * Dependencies: All P2b.1–P2b.3 stage classes + Content_Generator,
+ *       Publisher, Image_Pipeline, Run_Stage_State, Audit_Writer.
+ *
+ * @see core/class-authority-pipeline.php — Orchestrator that calls these helpers.
+ * @see ARCHITECTURE.md                   — Phase 2b data flow.
+ */
+class PRAutoBlogger_Authority_Pipeline_Stages {
+
+	/**
+	 * Run the research fan-out stage.
+	 *
+	 * @param string                       $run_id       Pipeline run UUID.
+	 * @param string                       $item_key     Article-scoped item key.
+	 * @param PRAutoBlogger_Article_Idea   $idea         The idea being researched.
+	 * @param PRAutoBlogger_Cost_Tracker   $cost_tracker Pipeline cost tracker.
+	 * @param PRAutoBlogger_Research_Fanout $fanout       Fan-out instance.
+	 * @return array<int, array{sources: array, agent_role: string}> Per-agent results, or empty on quorum miss.
+	 */
+	public static function run_research(
+		string $run_id,
+		string $item_key,
+		PRAutoBlogger_Article_Idea $idea,
+		PRAutoBlogger_Cost_Tracker $cost_tracker,
+		PRAutoBlogger_Research_Fanout $fanout
+	): array {
+		PRAutoBlogger_Pipeline_Status::broadcast( __( 'Authority: running specialist research fan-out…', 'prautoblogger' ) );
+		PRAutoBlogger_Run_Stage_State::start( $run_id, 'research', 'researcher', $item_key );
+		$results = $fanout->dispatch( $run_id, $item_key, $idea, $cost_tracker );
+		if ( ! empty( $results ) ) {
+			PRAutoBlogger_Run_Stage_State::done( $run_id, 'research', 'researcher', $item_key, (string) wp_json_encode( array( 'agent_count' => count( $results ) ) ) );
+		} else {
+			PRAutoBlogger_Run_Stage_State::fail( $run_id, 'research', 'researcher', $item_key );
+		}
+		return $results;
+	}
+
+	/**
+	 * Run the curate (Research_Judge) stage.
+	 *
+	 * @param string                      $run_id       Pipeline run UUID.
+	 * @param string                      $item_key     Article-scoped item key.
+	 * @param array                       $fanout_results Results from research stage.
+	 * @param PRAutoBlogger_Research_Judge $judge        Judge instance.
+	 * @return array<int, array{url: string, title: string, quality_score?: float}> Kept sources.
+	 */
+	public static function run_curate(
+		string $run_id,
+		string $item_key,
+		array $fanout_results,
+		PRAutoBlogger_Research_Judge $judge
+	): array {
+		PRAutoBlogger_Pipeline_Status::broadcast( __( 'Authority: curating research sources…', 'prautoblogger' ) );
+		return $judge->curate( $run_id, $item_key, $fanout_results );
+	}
+
+	/**
+	 * Run the draft (Content_Generator) stage.
+	 *
+	 * @param string                                   $run_id       Pipeline run UUID.
+	 * @param string                                   $item_key     Article-scoped item key.
+	 * @param PRAutoBlogger_Article_Idea               $idea         The idea to draft.
+	 * @param PRAutoBlogger_Cost_Tracker               $cost_tracker Pipeline cost tracker.
+	 * @param PRAutoBlogger_Content_Generator|null     $generator    Optional override (tests).
+	 * @return string Draft HTML content.
+	 */
+	public static function run_draft(
+		string $run_id,
+		string $item_key,
+		PRAutoBlogger_Article_Idea $idea,
+		PRAutoBlogger_Cost_Tracker $cost_tracker,
+		?PRAutoBlogger_Content_Generator $generator = null
+	): string {
+		PRAutoBlogger_Pipeline_Status::broadcast( __( 'Authority: generating article draft…', 'prautoblogger' ) );
+		if ( null === $generator ) {
+			$llm       = new PRAutoBlogger_OpenRouter_Provider();
+			$generator = new PRAutoBlogger_Content_Generator( $llm, $cost_tracker );
+			$generator->set_run_item( $run_id, $item_key );
+		}
+		return $generator->generate( $idea );
+	}
+
+	/**
+	 * Run the editorial loop stage.
+	 *
+	 * @param string                          $run_id       Pipeline run UUID.
+	 * @param string                          $item_key     Article-scoped item key.
+	 * @param string                          $content      Draft HTML.
+	 * @param PRAutoBlogger_Article_Idea      $idea         The idea under review.
+	 * @param PRAutoBlogger_Cost_Tracker      $cost_tracker Pipeline cost tracker.
+	 * @param PRAutoBlogger_Editorial_Loop    $editorial    Editorial loop instance.
+	 * @return array{content: string, escalated: bool} Result: content and escalation flag.
+	 */
+	public static function run_editorial(
+		string $run_id,
+		string $item_key,
+		string $content,
+		PRAutoBlogger_Article_Idea $idea,
+		PRAutoBlogger_Cost_Tracker $cost_tracker,
+		PRAutoBlogger_Editorial_Loop $editorial
+	): array {
+		PRAutoBlogger_Pipeline_Status::broadcast( __( 'Authority: running editorial loop…', 'prautoblogger' ) );
+		$reviewed = $editorial->run( $run_id, $item_key, $content, $idea, $cost_tracker );
+		return array(
+			'content'   => '' === $reviewed ? $content : $reviewed,
+			'escalated' => $editorial->was_escalated(),
+		);
+	}
+
+	/**
+	 * Run the SEO stage.
+	 *
+	 * @param string $run_id      Pipeline run UUID.
+	 * @param string $item_key    Article-scoped item key.
+	 * @param int    $post_id     Published/draft post ID.
+	 * @param array  $kept_sources Kept research sources from curate stage.
+	 * @param array  $peptide_ids  Related peptide post IDs.
+	 * @return float The computed citation_score.
+	 */
+	public static function run_seo(
+		string $run_id,
+		string $item_key,
+		int $post_id,
+		array $kept_sources,
+		array $peptide_ids
+	): float {
+		PRAutoBlogger_Pipeline_Status::broadcast( __( 'Authority: writing SEO meta…', 'prautoblogger' ) );
+		$seo_stage = new PRAutoBlogger_Seo_Stage();
+		return $seo_stage->run( $run_id, $item_key, $post_id, $kept_sources, $peptide_ids );
+	}
+
+	/**
+	 * Hold an article as draft (citation gate, escalation, or cost ceiling).
+	 *
+	 * Creates the draft post and suppresses image generation on it. Writes
+	 * a run_decisions row for the hold reason. Returns the decision verdict
+	 * string suitable for the result 'status' key.
+	 *
+	 * @param string                     $run_id       Pipeline run UUID.
+	 * @param string                     $item_key     Article-scoped item key.
+	 * @param string                     $content      Draft HTML content.
+	 * @param PRAutoBlogger_Article_Idea $idea         The article idea.
+	 * @param string                     $hold_reason  Short human-readable hold reason.
+	 * @param string                     $verdict      Decision verdict for audit row.
+	 * @param string                     $run_id_for_publisher Run ID passed to Publisher.
+	 * @return void
+	 */
+	public static function hold_as_draft(
+		string $run_id,
+		string $item_key,
+		string $content,
+		PRAutoBlogger_Article_Idea $idea,
+		string $hold_reason,
+		string $verdict,
+		string $run_id_for_publisher
+	): void {
+		PRAutoBlogger_Logger::instance()->info(
+			sprintf( 'Authority pipeline HOLD for "%s": %s', $idea->get_topic(), $hold_reason ),
+			'authority-pipeline'
+		);
+
+		// Save as draft with a neutral editorial review stub.
+		$publisher = new PRAutoBlogger_Publisher();
+		$review    = new PRAutoBlogger_Editorial_Review(
+			array(
+				'verdict'         => 'rejected',
+				'notes'           => $hold_reason,
+				'revised_content' => null,
+				'quality_score'   => 0.0,
+				'seo_score'       => 0.0,
+				'issues'          => array(),
+			)
+		);
+		$post_id = $publisher->save_as_draft( $content, $idea, $review, $run_id_for_publisher, null );
+
+		// Imagery gate: suppress image generation on held articles.
+		if ( $post_id > 0 ) {
+			update_post_meta( $post_id, '_prautoblogger_imagery_suppressed', '1' );
+		}
+
+		// Record the hold decision.
+		PRAutoBlogger_Audit_Writer::record_decision( $run_id, 'publish-gate', $verdict, $hold_reason );
+	}
+}

includes/core/class-authority-pipeline.php

@@ -0,0 +1,273 @@
+<?php
+declare(strict_types=1);
+
+/**
+ * phpcs:ignore WordPress.Files.FileName.InvalidClassFileName -- class naming convention differs from WordPress standard
+ *
+ * Authority-tier article generation pipeline orchestrator.
+ *
+ * What: Wires together P2b.1 (Research_Fanout + Research_Judge), P2b.2
+ *       (Editorial_Loop), and P2b.3 (Seo_Stage) into the 6-stage Authority
+ *       generation path. Gated behind the master flag
+ *       `prautoblogger_authority_pipeline_enabled` (default FALSE via
+ *       Tier_Router) — never runs in production until an operator opts in.
+ *
+ *       Stage chain:
+ *         1. research  — Research_Fanout::dispatch() → quorum miss → HOLD
+ *         2. curate    — Research_Judge::curate() → kept sources
+ *         3. draft     — Content_Generator::generate() → creates WP post
+ *         4. editorial — Editorial_Loop::run() → escalated → HOLD
+ *         5. seo       — Seo_Stage::run() → citation_score
+ *         6. gate      — citation_score >= threshold → publish; else HOLD
+ *
+ *       Cost ceiling: PRAutoBlogger_Cost_Ceiling_Exception → HOLD (never
+ *       force-complete). Per-run $0.50 ceiling inherited from Cost_Governor.
+ *
+ * Who triggers it: PRAutoBlogger_Article_Worker::generate() when tier='authority'.
+ * Dependencies: All P2b.1–P2b.3 stage classes, Publisher, Cost_Governor,
+ *       Run_Stage_State, Audit_Writer, Image_Pipeline (via Post_Assembler).
+ *
+ * @see providers/interface-authority-pipeline.php   — Interface.
+ * @see core/class-authority-pipeline-stages.php     — Stage helpers (split for 300-line rule).
+ * @see core/class-tier-router.php                   — Routes here on 'authority'.
+ * @see core/class-article-worker.php                — Economy fallback path.
+ * @see ARCHITECTURE.md                              — Phase 2b data flow.
+ */
+class PRAutoBlogger_Authority_Pipeline implements PRAutoBlogger_Authority_Pipeline_Interface {
+
+	/** Option key for the citation score publish gate threshold. */
+	public const OPTION_THRESHOLD = 'prautoblogger_citation_score_threshold';
+
+	/** Default threshold: 0.0 — gate always passes until calibrated. */
+	public const DEFAULT_THRESHOLD = 0.0;
+
+	/** @var PRAutoBlogger_Cost_Tracker Pipeline cost tracker. */
+	private PRAutoBlogger_Cost_Tracker $cost_tracker;
+
+	/** @var PRAutoBlogger_Research_Fanout|null Injected for tests. */
+	private ?PRAutoBlogger_Research_Fanout $fanout;
+
+	/** @var PRAutoBlogger_Research_Judge|null Injected for tests. */
+	private ?PRAutoBlogger_Research_Judge $judge;
+
+	/** @var PRAutoBlogger_Editorial_Loop|null Injected for tests. */
+	private ?PRAutoBlogger_Editorial_Loop $editorial;
+
+	/** @var PRAutoBlogger_Content_Generator|null Injected for tests. */
+	private ?PRAutoBlogger_Content_Generator $generator;
+
+	/**
+	 * @param PRAutoBlogger_Cost_Tracker           $cost_tracker Pipeline cost tracker.
+	 * @param PRAutoBlogger_Research_Fanout|null   $fanout       Optional fan-out override (tests).
+	 * @param PRAutoBlogger_Research_Judge|null    $judge        Optional judge override (tests).
+	 * @param PRAutoBlogger_Editorial_Loop|null    $editorial    Optional editorial loop override (tests).
+	 * @param PRAutoBlogger_Content_Generator|null $generator    Optional generator override (tests).
+	 */
+	public function __construct(
+		PRAutoBlogger_Cost_Tracker $cost_tracker,
+		?PRAutoBlogger_Research_Fanout $fanout = null,
+		?PRAutoBlogger_Research_Judge $judge = null,
+		?PRAutoBlogger_Editorial_Loop $editorial = null,
+		?PRAutoBlogger_Content_Generator $generator = null
+	) {
+		$this->cost_tracker = $cost_tracker;
+		$this->fanout       = $fanout;
+		$this->judge        = $judge;
+		$this->editorial    = $editorial;
+		$this->generator    = $generator;
+	}
+
+	/**
+	 * Run the full Authority-tier pipeline for one article.
+	 *
+	 * Catches PRAutoBlogger_Cost_Ceiling_Exception at the top level and
+	 * converts it to a HOLD (never a force-complete). All other exceptions
+	 * propagate to the Article_Worker's outer Throwable catch (which logs
+	 * + marks open stages as failed).
+	 *
+	 * Side effects: LLM API calls, DB writes, WP post creation, imagery
+	 * gate post-meta, audit rows (run_stages + run_decisions), Logger calls.
+	 *
+	 * @param string                     $run_id       Unique run identifier.
+	 * @param PRAutoBlogger_Article_Idea $idea         The article idea to process.
+	 * @param PRAutoBlogger_Cost_Tracker $cost_tracker Active cost tracker for this run.
+	 * @return array{generated: int, published: int, rejected: int, cost: float, status: string}
+	 */
+	public function run(
+		string $run_id,
+		PRAutoBlogger_Article_Idea $idea,
+		PRAutoBlogger_Cost_Tracker $cost_tracker
+	): array {
+		$item_key = PRAutoBlogger_Run_Stage_State::item_key_for_idea( $idea );
+		$result   = array(
+			'generated' => 0,
+			'published' => 0,
+			'rejected'  => 0,
+			'cost'      => 0.0,
+			'status'    => 'pending',
+		);
+
+		try {
+			$result = $this->execute_pipeline( $run_id, $item_key, $idea, $cost_tracker, $result );
+		} catch ( PRAutoBlogger_Cost_Ceiling_Exception $e ) {
+			// Ceiling breach: hold the article as draft — never force-complete.
+			PRAutoBlogger_Authority_Pipeline_Stages::hold_as_draft(
+				$run_id,
+				$item_key,
+				'<p>[Article generation halted by per-run cost ceiling.]</p>',
+				$idea,
+				$e->getMessage(),
+				'halted',
+				$run_id
+			);
+			$result['status'] = 'halted';
+			PRAutoBlogger_Logger::instance()->error(
+				sprintf( 'Authority pipeline halted for "%s" (cost ceiling): %s', $idea->get_topic(), $e->getMessage() ),
+				'authority-pipeline'
+			);
+		}
+
+		$result['cost'] = $cost_tracker->get_current_run_cost();
+		return $result;
+	}
+
+	// ── Private pipeline body ────────────────────────────────────────────
+
+	/**
+	 * Execute the 6-stage pipeline, returning the result array.
+	 *
+	 * Throws PRAutoBlogger_Cost_Ceiling_Exception on budget breach —
+	 * caller (run()) converts to HOLD.
+	 *
+	 * @param string                     $run_id       Run UUID.
+	 * @param string                     $item_key     Article-scoped item key.
+	 * @param PRAutoBlogger_Article_Idea $idea         The article idea.
+	 * @param PRAutoBlogger_Cost_Tracker $cost_tracker Pipeline cost tracker.
+	 * @param array                      $result       Result accumulator.
+	 * @return array{generated: int, published: int, rejected: int, cost: float, status: string}
+	 * @throws PRAutoBlogger_Cost_Ceiling_Exception When the cost ceiling is breached.
+	 */
+	private function execute_pipeline(
+		string $run_id,
+		string $item_key,
+		PRAutoBlogger_Article_Idea $idea,
+		PRAutoBlogger_Cost_Tracker $cost_tracker,
+		array $result
+	): array {
+		// Stage 1: Research fan-out.
+		$fanout   = $this->fanout ?? new PRAutoBlogger_Research_Fanout();
+		$fan_results = PRAutoBlogger_Authority_Pipeline_Stages::run_research( $run_id, $item_key, $idea, $cost_tracker, $fanout );
+		if ( empty( $fan_results ) ) {
+			PRAutoBlogger_Authority_Pipeline_Stages::hold_as_draft(
+				$run_id,
+				$item_key,
+				'',
+				$idea,
+				'Research quorum not met — holding for re-run.',
+				'quorum-miss',
+				$run_id
+			);
+			$result['status'] = 'held-quorum';
+			return $result;
+		}
+
+		// Stage 2: Curate.
+		$judge        = $this->judge ?? new PRAutoBlogger_Research_Judge();
+		$kept_sources = PRAutoBlogger_Authority_Pipeline_Stages::run_curate( $run_id, $item_key, $fan_results, $judge );
+
+		// Stage 3: Draft.
+		$draft_content    = PRAutoBlogger_Authority_Pipeline_Stages::run_draft( $run_id, $item_key, $idea, $cost_tracker, $this->generator );
+		$result['generated'] = 1;
+
+		// Stage 4: Editorial loop.
+		$llm           = new PRAutoBlogger_OpenRouter_Provider();
+		$chief_editor  = new PRAutoBlogger_Chief_Editor( $llm, $cost_tracker );
+		$rev_caller    = new PRAutoBlogger_Editorial_Revision_Caller( $llm, $cost_tracker );
+		$editorial     = $this->editorial ?? new PRAutoBlogger_Editorial_Loop( $chief_editor, $rev_caller );
+		$editorial_out = PRAutoBlogger_Authority_Pipeline_Stages::run_editorial(
+			$run_id,
+			$item_key,
+			$draft_content,
+			$idea,
+			$cost_tracker,
+			$editorial
+		);
+		$final_content = $editorial_out['content'];
+		$escalated     = $editorial_out['escalated'];
+
+		if ( $escalated ) {
+			PRAutoBlogger_Authority_Pipeline_Stages::hold_as_draft(
+				$run_id,
+				$item_key,
+				$final_content,
+				$idea,
+				'Editorial loop exhausted max rounds — held for human review.',
+				'escalated',
+				$run_id
+			);
+			$result['status'] = 'held-escalated';
+			return $result;
+		}
+
+		// Stage 3b: Save draft (needed for SEO stage and citation gate).
+		$publisher = new PRAutoBlogger_Publisher();
+		$stub_review = new PRAutoBlogger_Editorial_Review(
+			array(
+				'verdict'         => 'approved',
+				'notes'           => 'Authority pipeline editorial approved.',
+				'revised_content' => null,
+				'quality_score'   => 0.85,
+				'seo_score'       => 0.80,
+				'issues'          => array(),
+			)
+		);
+		$auto_publish = in_array( get_option( 'prautoblogger_auto_publish', '0' ), array( '1', 'yes' ), true );
+		$post_id = $publisher->save_as_draft( $final_content, $idea, $stub_review, $run_id, null );
+		PRAutoBlogger_Run_Stage_State::start( $run_id, 'publish', (string) PRAutoBlogger_Stage_Display_Map::default_agent_role( 'publish' ), $item_key );
+
+		// Stage 5: SEO.
+		$citation_score = PRAutoBlogger_Authority_Pipeline_Stages::run_seo( $run_id, $item_key, $post_id, $kept_sources, array() );
+
+		// Stage 6: Publish gate.
+		$threshold = (float) get_option( self::OPTION_THRESHOLD, self::DEFAULT_THRESHOLD );
+		if ( $citation_score >= $threshold && ! $escalated ) {
+			if ( $auto_publish ) {
+				wp_publish_post( $post_id );
+				// Image pipeline for published articles.
+				PRAutoBlogger_Post_Assembler::attach_generated_images(
+					$post_id,
+					$idea,
+					array(
+						'post_title'   => $idea->get_suggested_title(),
+						'post_content' => $final_content,
+					),
+					$cost_tracker
+				);
+				$result['published'] = 1;
+			}
+			PRAutoBlogger_Run_Stage_State::done( $run_id, 'publish', '', $item_key );
+			PRAutoBlogger_Audit_Writer::record_decision(
+				$run_id,
+				'publish-gate',
+				'approved',
+				sprintf( 'citation_score=%.4f >= threshold=%.4f', $citation_score, $threshold ),
+				$citation_score
+			);
+			$result['status'] = 'published';
+		} else {
+			// Citation gate: hold (imagery suppressed).
+			update_post_meta( $post_id, '_prautoblogger_imagery_suppressed', '1' );
+			PRAutoBlogger_Run_Stage_State::done( $run_id, 'publish', '', $item_key );
+			PRAutoBlogger_Audit_Writer::record_decision(
+				$run_id,
+				'publish-gate',
+				'held',
+				sprintf( 'citation_score=%.4f < threshold=%.4f — held as draft.', $citation_score, $threshold ),
+				$citation_score
+			);
+			$result['status'] = 'held-citation';
+		}
+
+		return $result;
+	}
+}

includes/core/class-tier-router.php

@@ -0,0 +1,100 @@
+<?php
+declare(strict_types=1);
+
+/**
+ * phpcs:ignore WordPress.Files.FileName.InvalidClassFileName -- class naming convention differs from WordPress standard
+ *
+ * Per-category generation tier router for the Authority pipeline.
+ *
+ * What: Resolves whether a given article idea should enter the Authority
+ *       pipeline or fall through to the Economy single-pass. The master
+ *       switch (`prautoblogger_authority_pipeline_enabled`) defaults FALSE,
+ *       which guarantees byte-identical behaviour to today — no articles
+ *       ever touch the Authority path unless an operator explicitly enables
+ *       the flag. When the flag is ON, per-category overrides in
+ *       `prautoblogger_category_tiers` demote specific categories to
+ *       Economy; every other category (unclassified, new, missing) stays
+ *       at the Authority default.
+ *
+ * Who triggers it: PRAutoBlogger_Article_Worker::generate() (P2b.4).
+ * Dependencies: WordPress get_option(), PRAutoBlogger_Article_Idea.
+ *
+ * @see providers/interface-tier-router.php    — Interface this class implements.
+ * @see core/class-article-worker.php          — Call site (3-line tier check).
+ * @see core/class-authority-pipeline.php      — Authority path executed on 'authority'.
+ * @see ARCHITECTURE.md                        — Phase 2b tier routing.
+ */
+class PRAutoBlogger_Tier_Router implements PRAutoBlogger_Tier_Router_Interface {
+
+	/** Option key for the master Authority pipeline feature flag. */
+	public const OPTION_MASTER_FLAG = 'prautoblogger_authority_pipeline_enabled';
+
+	/** Option key for the per-category tier map (serialized array). */
+	public const OPTION_CATEGORY_TIERS = 'prautoblogger_category_tiers';
+
+	/** Default tier when a category has no explicit override: Authority. */
+	private const DEFAULT_TIER = 'authority';
+
+	/**
+	 * Resolve the generation tier for an article idea.
+	 *
+	 * Returns 'economy' immediately when the master flag is OFF — this is
+	 * the production default and must guarantee zero behaviour change
+	 * relative to the pre-P2b.4 codebase.
+	 *
+	 * When the master flag is ON, looks up the idea's article_type in the
+	 * per-category tier map. Values of 'economy' explicitly demote that
+	 * category. Any other value, or no entry at all, keeps the Authority
+	 * default.
+	 *
+	 * Side effects: two get_option() calls (cached by WordPress object cache).
+	 *
+	 * @param PRAutoBlogger_Article_Idea $idea The article idea to route.
+	 * @return string 'authority' or 'economy'
+	 */
+	public function resolve( PRAutoBlogger_Article_Idea $idea ): string {
+		if ( ! $this->is_master_flag_on() ) {
+			return 'economy';
+		}
+
+		return $this->resolve_from_category( $idea->get_article_type() );
+	}
+
+	// ── Private helpers ──────────────────────────────────────────────────
+
+	/**
+	 * Whether the Authority pipeline master switch is enabled.
+	 *
+	 * The option defaults to false (disabled). Operators must explicitly
+	 * set it to '1' or true via wp_options / WP admin to enable the path.
+	 *
+	 * @return bool
+	 */
+	private function is_master_flag_on(): bool {
+		$flag = get_option( self::OPTION_MASTER_FLAG, false );
+		return in_array( $flag, array( '1', true, 1 ), true );
+	}
+
+	/**
+	 * Resolve tier from the per-category tier map.
+	 *
+	 * The map is a serialized PHP array (stored via WordPress options) of
+	 * `['category_slug' => 'economy']`. Only 'economy' is a meaningful
+	 * explicit value — anything else (including 'authority') is treated
+	 * as "keep the default".
+	 *
+	 * Unrecognised or empty maps → default Authority tier (additive safety).
+	 *
+	 * @param string $article_type Article type / category slug from the idea.
+	 * @return string 'authority' or 'economy'
+	 */
+	private function resolve_from_category( string $article_type ): string {
+		$raw = get_option( self::OPTION_CATEGORY_TIERS, array() );
+		$map = is_array( $raw ) ? $raw : array();
+
+		$tier = $map[ $article_type ] ?? self::DEFAULT_TIER;
+
+		// Only 'economy' is a valid explicit demote; any other value defaults.
+		return 'economy' === $tier ? 'economy' : 'authority';
+	}
+}

includes/providers/interface-authority-pipeline.php

@@ -0,0 +1,41 @@
+<?php
+/**
+ * Authority Pipeline Interface
+ *
+ * Contract for the full Authority-tier article generation pipeline.
+ *
+ * @package PRAutoBlogger
+ * @since 0.31.0
+ */
+
+declare(strict_types=1);
+
+if ( ! defined( 'ABSPATH' ) ) {
+	exit;
+}
+
+/**
+ * Full Authority-tier article generation pipeline.
+ *
+ * Implementations must orchestrate: research → curate → draft →
+ * editorial → seo → publish gate, with cost-governor reserve/settle
+ * on every stage and cost-ceiling halt → HOLD semantics.
+ *
+ * @see core/class-authority-pipeline.php — Production implementation.
+ */
+interface PRAutoBlogger_Authority_Pipeline_Interface {
+
+	/**
+	 * Run the full Authority-tier pipeline for one article.
+	 *
+	 * @param string                     $run_id       Unique run identifier.
+	 * @param PRAutoBlogger_Article_Idea $idea         The article idea to process.
+	 * @param PRAutoBlogger_Cost_Tracker $cost_tracker Active cost tracker for this run.
+	 * @return array{generated: int, published: int, rejected: int, cost: float, status: string} Pipeline result.
+	 */
+	public function run(
+		string $run_id,
+		PRAutoBlogger_Article_Idea $idea,
+		PRAutoBlogger_Cost_Tracker $cost_tracker
+	): array;
+}

includes/providers/interface-tier-router.php

@@ -0,0 +1,35 @@
+<?php
+/**
+ * Tier Router Interface
+ *
+ * Contract for resolving the generation tier (authority / economy) for an article idea.
+ *
+ * @package PRAutoBlogger
+ * @since 0.31.0
+ */
+
+declare(strict_types=1);
+
+if ( ! defined( 'ABSPATH' ) ) {
+	exit;
+}
+
+/**
+ * Resolves Authority vs Economy generation tier for a given article idea.
+ *
+ * Implementations read the per-category tier map and the master feature flag.
+ * When the master flag is OFF, resolve() MUST return 'economy' unconditionally
+ * to guarantee zero behaviour change in production.
+ *
+ * @see core/class-tier-router.php — Production implementation.
+ */
+interface PRAutoBlogger_Tier_Router_Interface {
+
+	/**
+	 * Resolve the generation tier for an article idea.
+	 *
+	 * @param PRAutoBlogger_Article_Idea $idea The article idea to route.
+	 * @return string 'authority' or 'economy'
+	 */
+	public function resolve( PRAutoBlogger_Article_Idea $idea ): string;
+}

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:           0.30.0
+ * Version:           0.31.0
  * 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', '0.30.0' );
+define( 'PRAUTOBLOGGER_VERSION', '0.31.0' );
 define( 'PRAUTOBLOGGER_DB_VERSION', '1.4.0' );  // No schema change in v0.30.0 (Seo_Stage is additive code only).
 define( 'PRAUTOBLOGGER_DEFAULT_RUN_CEILING_USD', 0.50 );
 define( 'PRAUTOBLOGGER_DEFAULT_REQUEST_JSON_RETENTION_DAYS', 14 );

tests/unit/Core/AuthorityPipelineTest.php

@@ -0,0 +1,402 @@
+<?php
+/**
+ * Tests for PRAutoBlogger_Authority_Pipeline and tier routing integration.
+ *
+ * Covers: Economy path taken when flag OFF (proven via TierRouter unit tests),
+ * cost ceiling halt -> draft hold, citation gate (below/at threshold),
+ * imagery suppressed on held articles, and stage order via mock calls.
+ *
+ * All dependencies that would make HTTP calls are mocked or stubbed.
+ *
+ * @package PRAutoBlogger\Tests\Core
+ */
+
+namespace PRAutoBlogger\Tests\Core;
+
+use PRAutoBlogger\Tests\BaseTestCase;
+use Brain\Monkey\Functions;
+
+class AuthorityPipelineTest extends BaseTestCase {
+
+	/** @var object Mock $wpdb. */
+	private object $wpdb;
+
+	/** @var array Rows inserted to run_decisions. */
+	private array $decision_rows = array();
+
+	/** @var array Post meta written. */
+	private array $meta_written = array();
+
+	/** @var array Posts that had wp_publish_post() called. */
+	private array $published_posts = array();
+
+	protected function setUp(): void {
+		parent::setUp();
+
+		$this->decision_rows   = array();
+		$this->meta_written    = array();
+		$this->published_posts = array();
+
+		$this->wpdb         = $this->create_mock_wpdb();
+		$GLOBALS["wpdb"]    = $this->wpdb;
+		$this->wpdb->prefix = "wp_";
+
+		$this->wpdb->method( "prepare" )->willReturnCallback(
+			static fn( $sql, ...$args ) => $sql . " /* " . implode( ",", array_map( "strval", $args ) ) . " */"
+		);
+
+		$test = $this;
+		$this->wpdb->method( "insert" )->willReturnCallback(
+			function ( $table, $data ) use ( $test ) {
+				if ( false !== strpos( $table, "run_decisions" ) ) {
+					$test->decision_rows[] = $data;
+				}
+				return 1;
+			}
+		);
+
+		$this->wpdb->method( "get_var" )->willReturnCallback(
+			static function ( $sql ) {
+				if ( false !== strpos( $sql, "SHOW TABLES" ) ) {
+					return "wp_prautoblogger_run_decisions";
+				}
+				return null;
+			}
+		);
+		$this->wpdb->method( "query" )->willReturn( 1 );
+		$this->wpdb->method( "get_row" )->willReturn( null );
+		$this->wpdb->method( "get_col" )->willReturn( array() );
+
+		\PRAutoBlogger_Audit_Writer::flush_cache();
+		\PRAutoBlogger_Run_Stage_State::flush_cache();
+
+		// Common WP function stubs.
+		Functions\when( "current_time" )->justReturn( "2026-06-24 00:00:00" );
+		Functions\when( "wp_json_encode" )->alias( "json_encode" );
+		Functions\when( "gmdate" )->alias( "gmdate" );
+		Functions\when( "__" )->alias( static fn( $s ) => $s );
+		Functions\when( "sanitize_text_field" )->alias( static fn( $s ) => $s );
+		Functions\when( "wp_kses_post" )->alias( static fn( $s ) => $s );
+		Functions\when( "wp_strip_all_tags" )->alias( "strip_tags" );
+		Functions\when( "apply_filters" )->alias( static fn( $tag, $val ) => $val );
+		Functions\when( "do_action" )->justReturn( null );
+		Functions\when( "wp_insert_post" )->justReturn( 42 );
+		Functions\when( "wp_set_post_terms" )->justReturn( array() );
+		Functions\when( "wp_set_post_categories" )->justReturn( array() );
+		Functions\when( "wp_set_post_tags" )->justReturn( array() );
+		Functions\when( "post_type_exists" )->justReturn( false );
+		Functions\when( "get_users" )->justReturn( array( 1 ) );
+		Functions\when( "get_term_by" )->justReturn( false );
+		Functions\when( "wp_insert_term" )->justReturn( array( "term_id" => 1 ) );
+		Functions\when( "absint" )->alias( "intval" );
+		Functions\when( "is_wp_error" )->justReturn( false );
+		Functions\when( "get_post_meta" )->justReturn( "" );
+
+		$test = $this;
+		Functions\when( "wp_publish_post" )->alias(
+			function ( $id ) use ( $test ) {
+				$test->published_posts[] = $id;
+			}
+		);
+
+		Functions\when( "update_post_meta" )->alias(
+			function ( $post_id, $key, $value ) use ( $test ) {
+				$test->meta_written[ $key ] = $value;
+				return true;
+			}
+		);
+
+		$this->stub_get_option( array(
+			"prautoblogger_log_level"                  => "error",
+			"prautoblogger_auto_publish"               => "0",
+			"prautoblogger_citation_score_threshold"   => 0.0,
+			"prautoblogger_writing_pipeline"           => "single_pass",
+			"prautoblogger_writing_model"              => "openai/gpt-4o-mini",
+			"prautoblogger_default_author"             => 1,
+		) );
+	}
+
+	protected function tearDown(): void {
+		\PRAutoBlogger_Audit_Writer::flush_cache();
+		\PRAutoBlogger_Run_Stage_State::flush_cache();
+		unset( $GLOBALS["wpdb"] );
+		parent::tearDown();
+	}
+
+	// -- Cost ceiling halt ------------------------------------------------
+
+	/**
+	 * When the research stage throws PRAutoBlogger_Cost_Ceiling_Exception,
+	 * the pipeline must HOLD the article as draft (status="halted") and
+	 * must NOT force-complete or publish it.
+	 */
+	public function test_cost_ceiling_halt_holds_article(): void {
+		$fanout   = $this->make_fanout_throwing_ceiling();
+		$tracker  = $this->make_cost_tracker_stub();
+		$pipeline = new \PRAutoBlogger_Authority_Pipeline( $tracker, $fanout );
+		$result   = $pipeline->run( "run-ceiling", $this->make_idea(), $tracker );
+
+		$this->assertSame( "halted", $result["status"] );
+		$this->assertSame( 0, $result["published"] );
+		$this->assertEmpty( $this->published_posts );
+	}
+
+	// -- Citation gate ----------------------------------------------------
+
+	/**
+	 * When citation_score (computed by Seo_Stage from kept_sources) is below
+	 * the threshold, the article must be held as draft, not published.
+	 * auto_publish=1 is set so the only thing blocking publish is the gate.
+	 */
+	public function test_citation_gate_holds_below_threshold(): void {
+		$this->stub_get_option( array(
+			"prautoblogger_log_level"                => "error",
+			"prautoblogger_auto_publish"             => "1",
+			"prautoblogger_citation_score_threshold" => 0.8,
+			"prautoblogger_writing_pipeline"         => "single_pass",
+			"prautoblogger_writing_model"            => "openai/gpt-4o-mini",
+			"prautoblogger_default_author"           => 1,
+		) );
+
+		$low_quality_sources = array(
+			array( "url" => "https://a.com", "title" => "A", "quality_score" => 0.3 ),
+		);
+
+		$fanout    = $this->make_fanout_stub( $this->make_fanout_results( $low_quality_sources ) );
+		$judge     = $this->make_judge_stub( $low_quality_sources );
+		$loop      = $this->make_editorial_loop_stub( "<p>approved content</p>", false );
+		$generator = $this->make_generator_stub( "<p>draft content</p>" );
+		$tracker   = $this->make_cost_tracker_stub();
+		$pipeline  = new \PRAutoBlogger_Authority_Pipeline( $tracker, $fanout, $judge, $loop, $generator );
+		$result    = $pipeline->run( "run-citation-low", $this->make_idea(), $tracker );
+
+		$this->assertSame( "held-citation", $result["status"] );
+		$this->assertSame( 0, $result["published"] );
+		$this->assertEmpty( $this->published_posts );
+		$this->assertArrayHasKey( "_prautoblogger_imagery_suppressed", $this->meta_written );
+		$this->assertSame( "1", $this->meta_written["_prautoblogger_imagery_suppressed"] );
+	}
+
+	/**
+	 * When citation_score equals the threshold, the gate passes.
+	 * auto_publish=0 so we verify status is not "held-citation".
+	 */
+	public function test_citation_gate_passes_at_threshold(): void {
+		$this->stub_get_option( array(
+			"prautoblogger_log_level"                => "error",
+			"prautoblogger_auto_publish"             => "0",
+			"prautoblogger_citation_score_threshold" => 0.8,
+			"prautoblogger_writing_pipeline"         => "single_pass",
+			"prautoblogger_writing_model"            => "openai/gpt-4o-mini",
+			"prautoblogger_default_author"           => 1,
+		) );
+
+		$high_quality_sources = array(
+			array( "url" => "https://a.com", "title" => "A", "quality_score" => 0.8 ),
+		);
+
+		$fanout    = $this->make_fanout_stub( $this->make_fanout_results( $high_quality_sources ) );
+		$judge     = $this->make_judge_stub( $high_quality_sources );
+		$loop      = $this->make_editorial_loop_stub( "<p>approved content</p>", false );
+		$generator = $this->make_generator_stub( "<p>draft content</p>" );
+		$tracker   = $this->make_cost_tracker_stub();
+		$pipeline  = new \PRAutoBlogger_Authority_Pipeline( $tracker, $fanout, $judge, $loop, $generator );
+		$result    = $pipeline->run( "run-citation-at", $this->make_idea(), $tracker );
+
+		$this->assertNotSame( "held-citation", $result["status"] );
+		$this->assertArrayNotHasKey( "_prautoblogger_imagery_suppressed", $this->meta_written );
+	}
+
+	// -- Imagery gate -----------------------------------------------------
+
+	/**
+	 * When the editorial loop escalates (article held), imagery must be
+	 * suppressed via _prautoblogger_imagery_suppressed=1 post-meta.
+	 */
+	public function test_imagery_suppressed_on_hold(): void {
+		$sources   = array( array( "url" => "https://a.com", "title" => "A", "quality_score" => 0.9 ) );
+		$fanout    = $this->make_fanout_stub( $this->make_fanout_results( $sources ) );
+		$judge     = $this->make_judge_stub( $sources );
+		$loop      = $this->make_editorial_loop_stub( "", true );
+		$generator = $this->make_generator_stub( "<p>draft content</p>" );
+		$tracker   = $this->make_cost_tracker_stub();
+		$pipeline  = new \PRAutoBlogger_Authority_Pipeline( $tracker, $fanout, $judge, $loop, $generator );
+		$result    = $pipeline->run( "run-imagery", $this->make_idea(), $tracker );
+
+		$this->assertSame( "held-escalated", $result["status"] );
+		$this->assertArrayHasKey( "_prautoblogger_imagery_suppressed", $this->meta_written );
+		$this->assertSame( "1", $this->meta_written["_prautoblogger_imagery_suppressed"] );
+	}
+
+	// -- Economy path flag check ------------------------------------------
+
+	/**
+	 * When the master flag is OFF, Tier_Router returns "economy".
+	 * The Authority pipeline is never instantiated or called.
+	 */
+	public function test_master_flag_off_economy_path_used(): void {
+		Functions\when( "get_option" )->alias(
+			function ( $name, $default = false ) {
+				if ( "prautoblogger_authority_pipeline_enabled" === $name ) {
+					return false;
+				}
+				if ( "prautoblogger_log_level" === $name ) {
+					return "error";
+				}
+				return $default;
+			}
+		);
+
+		$idea   = $this->make_idea();
+		$router = new \PRAutoBlogger_Tier_Router();
+		$tier   = $router->resolve( $idea );
+
+		$this->assertSame( "economy", $tier );
+		$this->assertArrayNotHasKey( "_prautoblogger_imagery_suppressed", $this->meta_written );
+	}
+
+	// -- Stage ordering ---------------------------------------------------
+
+	/**
+	 * Stage order: research -> curate -> draft -> editorial -> seo -> gate.
+	 * Verify that fanout, judge, generator, and editorial loop are called.
+	 */
+	public function test_authority_chain_runs_stages_in_order(): void {
+		$sources = array( array( "url" => "https://a.com", "title" => "A", "quality_score" => 0.9 ) );
+		$called  = array();
+
+		$fanout = $this->getMockBuilder( \PRAutoBlogger_Research_Fanout::class )
+			->disableOriginalConstructor()
+			->onlyMethods( array( "dispatch" ) )
+			->getMock();
+		$fanout->expects( $this->once() )->method( "dispatch" )
+			->willReturnCallback(
+				function () use ( &$called, $sources ) {
+					$called[] = "research";
+					return $this->make_fanout_results( $sources );
+				}
+			);
+
+		$judge = $this->getMockBuilder( \PRAutoBlogger_Research_Judge::class )
+			->disableOriginalConstructor()
+			->onlyMethods( array( "curate" ) )
+			->getMock();
+		$judge->expects( $this->once() )->method( "curate" )
+			->willReturnCallback(
+				function () use ( &$called, $sources ) {
+					$called[] = "curate";
+					return $sources;
+				}
+			);
+
+		$generator = $this->getMockBuilder( \PRAutoBlogger_Content_Generator::class )
+			->disableOriginalConstructor()
+			->onlyMethods( array( "generate" ) )
+			->getMock();
+		$generator->expects( $this->once() )->method( "generate" )
+			->willReturnCallback(
+				function () use ( &$called ) {
+					$called[] = "draft";
+					return "<p>draft content</p>";
+				}
+			);
+
+		$loop = $this->getMockBuilder( \PRAutoBlogger_Editorial_Loop::class )
+			->disableOriginalConstructor()
+			->onlyMethods( array( "run", "was_escalated" ) )
+			->getMock();
+		$loop->expects( $this->once() )->method( "run" )
+			->willReturnCallback(
+				function () use ( &$called ) {
+					$called[] = "editorial";
+					return "<p>approved content</p>";
+				}
+			);
+		$loop->method( "was_escalated" )->willReturn( false );
+
+		$tracker  = $this->make_cost_tracker_stub();
+		$pipeline = new \PRAutoBlogger_Authority_Pipeline( $tracker, $fanout, $judge, $loop, $generator );
+		$result   = $pipeline->run( "run-order", $this->make_idea(), $tracker );
+
+		$this->assertSame( array( "research", "curate", "draft", "editorial" ), $called );
+		$this->assertIsArray( $result );
+		$this->assertArrayHasKey( "status", $result );
+	}
+
+	// -- Helpers ----------------------------------------------------------
+
+	private function make_idea(): \PRAutoBlogger_Article_Idea {
+		return new \PRAutoBlogger_Article_Idea( array(
+			"topic"           => "BPC-157",
+			"article_type"    => "guide",
+			"suggested_title" => "BPC-157 Guide",
+			"summary"         => "Comprehensive guide.",
+			"score"           => 0.9,
+		) );
+	}
+
+	private function make_cost_tracker_stub(): object {
+		$tracker = $this->getMockBuilder( \PRAutoBlogger_Cost_Tracker::class )
+			->disableOriginalConstructor()
+			->onlyMethods( array( "get_run_id", "get_current_run_cost", "log_api_call" ) )
+			->getMock();
+		$tracker->method( "get_run_id" )->willReturn( "run-test" );
+		$tracker->method( "get_current_run_cost" )->willReturn( 0.01 );
+		return $tracker;
+	}
+
+	private function make_fanout_throwing_ceiling(): object {
+		$fanout = $this->getMockBuilder( \PRAutoBlogger_Research_Fanout::class )
+			->disableOriginalConstructor()
+			->onlyMethods( array( "dispatch" ) )
+			->getMock();
+		$fanout->method( "dispatch" )->willThrowException(
+			new \PRAutoBlogger_Cost_Ceiling_Exception( "Test cost ceiling breach." )
+		);
+		return $fanout;
+	}
+
+	private function make_fanout_stub( array $results ): object {
+		$fanout = $this->getMockBuilder( \PRAutoBlogger_Research_Fanout::class )
+			->disableOriginalConstructor()
+			->onlyMethods( array( "dispatch" ) )
+			->getMock();
+		$fanout->method( "dispatch" )->willReturn( $results );
+		return $fanout;
+	}
+
+	private function make_judge_stub( array $kept_sources ): object {
+		$judge = $this->getMockBuilder( \PRAutoBlogger_Research_Judge::class )
+			->disableOriginalConstructor()
+			->onlyMethods( array( "curate" ) )
+			->getMock();
+		$judge->method( "curate" )->willReturn( $kept_sources );
+		return $judge;
+	}
+
+	private function make_editorial_loop_stub( string $content, bool $escalated ): object {
+		$loop = $this->getMockBuilder( \PRAutoBlogger_Editorial_Loop::class )
+			->disableOriginalConstructor()
+			->onlyMethods( array( "run", "was_escalated" ) )
+			->getMock();
+		$loop->method( "run" )->willReturn( $content );
+		$loop->method( "was_escalated" )->willReturn( $escalated );
+		return $loop;
+	}
+
+	private function make_generator_stub( string $content ): object {
+		$gen = $this->getMockBuilder( \PRAutoBlogger_Content_Generator::class )
+			->disableOriginalConstructor()
+			->onlyMethods( array( "generate" ) )
+			->getMock();
+		$gen->method( "generate" )->willReturn( $content );
+		return $gen;
+	}
+
+	private function make_fanout_results( array $sources ): array {
+		return array(
+			array( "sources" => $sources, "agent_role" => "mechanisms" ),
+			array( "sources" => $sources, "agent_role" => "clinical" ),
+		);
+	}
+}

tests/unit/Core/TierRouterTest.php

@@ -0,0 +1,123 @@
+<?php
+/**
+ * Tests for PRAutoBlogger_Tier_Router.
+ *
+ * Covers: master flag OFF always returns 'economy', unclassified category
+ * defaults to authority, explicit 'economy' demotion, explicit 'authority'
+ * entry treated as default authority.
+ *
+ * No LLM calls — the router is a pure option-read + conditional.
+ *
+ * @package PRAutoBlogger\Tests\Core
+ */
+
+namespace PRAutoBlogger\Tests\Core;
+
+use PRAutoBlogger\Tests\BaseTestCase;
+use Brain\Monkey\Functions;
+
+class TierRouterTest extends BaseTestCase {
+
+	/** @var \PRAutoBlogger_Article_Idea Shared idea fixture. */
+	private \PRAutoBlogger_Article_Idea $idea;
+
+	protected function setUp(): void {
+		parent::setUp();
+
+		$this->idea = new \PRAutoBlogger_Article_Idea( array(
+			'topic'           => 'BPC-157 overview',
+			'article_type'    => 'guide',
+			'suggested_title' => 'BPC-157 Guide',
+			'summary'         => 'Comprehensive guide.',
+			'score'           => 0.9,
+		) );
+	}
+
+	// ── Master flag OFF ──────────────────────────────────────────────────
+
+	/**
+	 * When the master flag is OFF (default false), resolve() must always
+	 * return 'economy' regardless of category map contents.
+	 *
+	 * This is the critical proof that P2b.4 deployment = zero behavior change.
+	 */
+	public function test_master_flag_off_always_returns_economy(): void {
+		$this->stub_get_option( array(
+			'prautoblogger_authority_pipeline_enabled' => false,
+			'prautoblogger_category_tiers'             => array( 'guide' => 'authority' ),
+		) );
+
+		$router = new \PRAutoBlogger_Tier_Router();
+		$this->assertSame( 'economy', $router->resolve( $this->idea ) );
+	}
+
+	/**
+	 * String '0' is also a falsy master flag — must return 'economy'.
+	 */
+	public function test_master_flag_string_zero_returns_economy(): void {
+		$this->stub_get_option( array(
+			'prautoblogger_authority_pipeline_enabled' => '0',
+		) );
+
+		$router = new \PRAutoBlogger_Tier_Router();
+		$this->assertSame( 'economy', $router->resolve( $this->idea ) );
+	}
+
+	// ── Master flag ON — category routing ────────────────────────────────
+
+	/**
+	 * When flag is ON and the idea's category is NOT in the tier map,
+	 * the default Authority tier must apply.
+	 */
+	public function test_unclassified_category_defaults_authority(): void {
+		$this->stub_get_option( array(
+			'prautoblogger_authority_pipeline_enabled' => '1',
+			'prautoblogger_category_tiers'             => array( 'news' => 'economy' ),
+		) );
+
+		$router = new \PRAutoBlogger_Tier_Router();
+		// 'guide' is not in the tier map → default authority.
+		$this->assertSame( 'authority', $router->resolve( $this->idea ) );
+	}
+
+	/**
+	 * When flag is ON and the idea's category is explicitly set to 'economy'
+	 * in the tier map, resolve() must return 'economy'.
+	 */
+	public function test_explicitly_demoted_category_returns_economy(): void {
+		$this->stub_get_option( array(
+			'prautoblogger_authority_pipeline_enabled' => '1',
+			'prautoblogger_category_tiers'             => array( 'guide' => 'economy' ),
+		) );
+
+		$router = new \PRAutoBlogger_Tier_Router();
+		$this->assertSame( 'economy', $router->resolve( $this->idea ) );
+	}
+
+	/**
+	 * When flag is ON and the idea's category is explicitly set to 'authority'
+	 * in the tier map (redundant but valid), resolve() must return 'authority'.
+	 */
+	public function test_authority_category_returns_authority(): void {
+		$this->stub_get_option( array(
+			'prautoblogger_authority_pipeline_enabled' => '1',
+			'prautoblogger_category_tiers'             => array( 'guide' => 'authority' ),
+		) );
+
+		$router = new \PRAutoBlogger_Tier_Router();
+		$this->assertSame( 'authority', $router->resolve( $this->idea ) );
+	}
+
+	/**
+	 * When flag is ON and the tier map is empty, all categories default to 'authority'.
+	 */
+	public function test_empty_tier_map_defaults_authority(): void {
+		$this->stub_get_option( array(
+			'prautoblogger_authority_pipeline_enabled' => '1',
+			'prautoblogger_category_tiers'             => array(),
+		) );
+
+		$router = new \PRAutoBlogger_Tier_Router();
+		$this->assertSame( 'authority', $router->resolve( $this->idea ) );
+	}
+}