feat: brand identity v1.0.0 — Direction C Trusted Guide (theme v2.0.0-alpha.1)

Implements weeks 1–4 of the CMO brand identity sprint.

Key changes:
- CSS token system (assets/css/brand.css): full palette, verdict tokens, component styles
- Poppins/Inter/IBM Plex Mono Google Fonts loading with preload
- Full favicon/PWA/OG asset pack (peptide-repo-brand v1.0.0)
- 5-state verdict badge + card + evidence row components
- verdict_state + signal_row post meta on pr_peptide CPT
- Homepage hero: teal bg, new H1/subhead, lime search bar
- Archive verdict filter chips (CSS + pre_get_posts query hook)
- Affiliate disclosure component (3 contexts)
- page-how-we-review.php + page-about.php templates
- Footer Our Method links
- a11y: skip-to-content, reduced-motion, aria on verdict badges

QA: PASS (0 blockers) — qa-reviews/peptide-starter-theme/2026-04-26-a2bff59.md
Staging verified: https://staging.peptiderepo.com

site.webmanifest

@@ -0,0 +1,14 @@
+{
+  "name": "Peptide Repo",
+  "short_name": "Peptide Repo",
+  "description": "What the research really says — verdict-driven peptide science.",
+  "start_url": "/",
+  "scope": "/",
+  "display": "standalone",
+  "background_color": "#FAFAF7",
+  "theme_color": "#1B8A92",
+  "icons": [
+    {"src": "/wp-content/themes/peptide-starter/assets/brand/icon-192.png", "sizes": "192x192", "type": "image/png", "purpose": "any maskable"},
+    {"src": "/wp-content/themes/peptide-starter/assets/brand/icon-512.png", "sizes": "512x512", "type": "image/png", "purpose": "any maskable"}
+  ]
+}