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

assets/brand/logo-mark-small.svg

@@ -0,0 +1,5 @@
+<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 80 80" role="img" aria-label="Peptide Repo">
+  <rect x="0" y="0" width="72" height="72" rx="14" fill="#1B8A92"/>
+  <text x="36" y="52" text-anchor="middle" font-family="Poppins, sans-serif" font-weight="700" font-size="38" fill="#FFFFFF" letter-spacing="0.5">PR</text>
+  <circle cx="66" cy="66" r="13" fill="#7FD600"/>
+</svg>