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>

package.json

@@ -12,30 +12,57 @@
     "build:storybook": "storybook build",
     "build:tokens": "node style-dictionary/config.js",
     "type-check": "tsc --noEmit",
-    "chromatic": "chromatic --exit-zero-on-changes"
+    "lint": "eslint src/",
+    "lint:fix": "eslint src/ --fix",
+    "format": "prettier --write 'src/**/*.{ts,tsx}'",
+    "format:check": "prettier --check 'src/**/*.{ts,tsx}'",
+    "test": "vitest run --passWithNoTests",
+    "test:watch": "vitest",
+    "chromatic": "chromatic --exit-zero-on-changes",
+    "prepare": "husky"
   },
   "dependencies": {
     "@emotion/react": "^11.13.0",
     "@emotion/styled": "^11.13.0",
+    "@mui/icons-material": "^5.16.0",
     "@mui/material": "^5.16.0",
     "@mui/system": "^5.16.0",
-    "@mui/icons-material": "^5.16.0",
     "react": "^18.3.0",
     "react-dom": "^18.3.0"
   },
   "devDependencies": {
+    "@eslint/js": "^9.39.4",
     "@storybook/addon-designs": "^8.0.0",
     "@storybook/addon-essentials": "^8.4.0",
     "@storybook/blocks": "^8.4.0",
     "@storybook/react": "^8.4.0",
     "@storybook/react-vite": "^8.4.0",
+    "@testing-library/jest-dom": "^6.9.1",
+    "@testing-library/react": "^16.3.2",
     "@types/react": "^18.3.0",
     "@types/react-dom": "^18.3.0",
     "@vitejs/plugin-react": "^4.3.0",
     "chromatic": "^11.0.0",
+    "eslint": "^9.39.4",
+    "eslint-config-prettier": "^10.1.8",
+    "eslint-plugin-jsx-a11y": "^6.10.2",
+    "eslint-plugin-react": "^7.37.5",
+    "eslint-plugin-react-hooks": "^7.0.1",
+    "husky": "^9.1.7",
+    "jsdom": "^29.0.1",
+    "lint-staged": "^16.4.0",
+    "prettier": "^3.8.1",
     "storybook": "^8.4.0",
     "style-dictionary": "^4.2.0",
     "typescript": "^5.5.0",
-    "vite": "^5.4.0"
+    "typescript-eslint": "^8.57.2",
+    "vite": "^5.4.0",
+    "vitest": "^4.1.2"
+  },
+  "lint-staged": {
+    "src/**/*.{ts,tsx}": [
+      "eslint --fix",
+      "prettier --write"
+    ]
   }
 }