feat: Implement Request Interceptor Plugin (#14)

## Summary

Implements Request Interceptor Plugin wrapping Chrome's
`declarativeNetRequest` API.

**Closes #3**

## What's Changed

### Request Interceptor Plugin
- `enable()` - Apply auth rules as Chrome rules
- `disable()` - Remove all rules
- `updateRules()` - Refresh from storage
- `getRuleCount()` / `isAtLimit()` - Rule management
- Auto-enables on SDK ready
- Auto-updates when storage changes
- Event emission for observability

### Design
- `xmlhttprequest` resource type only (API calls)
- Rule IDs = array index + 1 (simple, predictable)
- `set` operation (replaces existing auth header)
- All rules priority 1
- Rejects >300 rules with clear error

## Dependencies
- Chrome Storage Plugin (#1)
- Pattern Matcher Plugin (#2)
- Chrome's `declarativeNetRequest` API

## Testing

- ✅ Linter: No errors (except expected `any` in SDK Kit plugin
signature)
- ✅ TypeScript: Compiles cleanly
- ⏭️ Manual testing: Will test in background worker (Issue #4)

## Next Steps

After merge:
- Issue #4: Background Service Worker (wire all 3 plugins together!)
- Then test the full extension!

Author: prosdev

.husky/commit-msg

@@ -0,0 +1,2 @@
+pnpm exec commitlint --edit "$1"
+

.husky/pre-commit

@@ -0,0 +1,11 @@
+# Get staged files
+files=$(git diff --cached --name-only --diff-filter=ACMR "*.ts" "*.tsx" "*.js" "*.jsx" | xargs)
+
+if [ -n "$files" ]; then
+  echo "Running Biome on staged files: $files"
+  pnpm lint-staged $files
+  git add $files
+fi
+
+# Run TypeScript type check
+pnpm type-check

biome.json

@@ -38,4 +38,3 @@
     }
   }
 }
-

commitlint.config.js

@@ -0,0 +1,7 @@
+export default {
+  extends: ['@commitlint/config-conventional'],
+  rules: {
+    'body-max-line-length': [2, 'always', 100],
+    'subject-case': [2, 'never', ['start-case', 'pascal-case', 'upper-case']],
+  },
+};

package.json

@@ -10,7 +10,9 @@
     "type-check": "tsc --noEmit",
     "lint": "biome check .",
     "lint:fix": "biome check --write .",
-    "format": "biome format --write ."
+    "format": "biome format --write .",
+    "prepare": "husky",
+    "lint-staged": "biome check --write --no-errors-on-unmatched"
   },
   "keywords": [
     "chrome-extension",
@@ -29,11 +31,14 @@
   },
   "devDependencies": {
     "@biomejs/biome": "^1.9.4",
+    "@commitlint/cli": "^20.2.0",
+    "@commitlint/config-conventional": "^20.2.0",
     "@types/chrome": "^0.0.278",
     "@types/react": "^19.0.2",
     "@types/react-dom": "^19.0.2",
     "@vitejs/plugin-react": "^4.3.4",
     "autoprefixer": "^10.4.20",
+    "husky": "^9.1.7",
     "postcss": "^8.4.49",
     "tailwindcss": "^3.4.17",
     "typescript": "^5.7.3",