Add workflow infrastructure — ESLint, Prettier, Husky, Vitest, 7 new skills

Phase 1: Session log archived (1096→91 lines), D031 token access convention
Phase 2: ESLint v9 + Prettier + jsx-a11y, initial config and lint fixes
Phase 3: 7 new skills (polish, harden, normalize, clarify, typeset, quieter, adapt)
         + Vercel reference docs, updated audit/review-component refs
Phase 4: Husky + lint-staged pre-commit hooks, preflight updated to 8 checks
Phase 5: Vitest + Testing Library + /write-tests skill

- Badge.tsx colour maps unified to CSS variables (D031)
- 5 empty interface→type alias fixes (Switch, Radio, Divider, IconButton, Link)

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

docs/memory/decisions-log.md

@@ -259,3 +259,13 @@ contradict a previous one.
 **Rationale:** A provider could be verified but have a broken/missing image URL. The boolean is the source of truth from the business layer. Image and logo are only rendered when `verified` is also true, preventing accidental display of unverified providers with images.
 **Affects:** ProviderCard API, data model expectations
 **Alternatives considered:** Deriving verified from imageUrl presence — rejected as it couples business logic (partner status) to content availability (image uploaded).
+
+### D031 — Token access convention: theme accessors for semantic, CSS vars for component
+**Date:** 2026-03-27
+**Category:** architecture
+**Decision:** Two token access methods are both valid, used by tier:
+- **`theme.palette.*`, `theme.typography.*`, `theme.spacing()`** — for semantic tokens that MUI maps into its theme (palette colours, typography variants, spacing). Used when the MUI theme callback is already available.
+- **`var(--fa-*)`** CSS variables — for component-tier tokens (badge sizes, card shadows, input dimensions) generated by Style Dictionary but not mapped into the MUI theme. Also acceptable for semantic tokens when the CSS variable form is more ergonomic (e.g., in colour maps, static styles).
+**Rationale:** The codebase naturally evolved this dual-path pattern. Semantic tokens are mapped into the MUI theme by `src/theme/index.ts`, making `theme.palette.*` the idiomatic MUI access path. Component-tier tokens exist only as CSS variables (Style Dictionary output). Forcing all access through one path would either require mapping every component token into MUI (over-engineering) or abandoning MUI's type-safe theme accessors (losing DX).
+**Affects:** All component files, `docs/conventions/component-conventions.md`, Badge.tsx (normalized to CSS vars for colour maps)
+**Alternatives considered:** CSS vars only — rejected because it loses MUI's TypeScript-safe theme API. Theme accessors only — rejected because component tokens aren't in the MUI theme.