Add TypeScript frontend build system with shared components

- Set up esbuild for fast TypeScript compilation of frontend code
- Create SharedHeader component with factories for main/admin/privacy pages
- Create SharedFooter component with standard and minimal variants
- Add frontend build scripts (build:frontend, watch:frontend, dev:full)
- Configure TypeScript for browser environment with DOM types
- Add example page demonstrating shared component usage
- Update .gitignore to exclude compiled frontend files

Benefits:
- Type-safe frontend components
- Consistent headers/footers across all pages
- Single source of truth for common UI elements
- Built-in i18n and theme toggle support

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-Authored-By: Claude <noreply@anthropic.com>

package.json

@@ -13,23 +13,24 @@
     "watch-css": "sass src/scss/main.scss public/style.css --watch --style=expanded --source-map",
     "dev-with-css": "concurrently \"npm run watch-css\" \"npm run dev\"",
     "dev-with-css:ts": "concurrently \"npm run watch-css\" \"npm run dev:ts\"",
-    "build": "npm run build:ts && npm run build-css && npm run copy-i18n",
+    "build": "npm run build:ts && npm run build-css && npm run build:frontend && npm run copy-i18n",
     "build:ts": "tsc",
     "copy-i18n": "mkdir -p dist/i18n/locales && cp -r src/i18n/locales/* dist/i18n/locales/",
     "test": "jest --runInBand --forceExit",
     "test:coverage": "jest --coverage",
     "lint": "eslint src/ tests/",
     "lint:fix": "eslint src/ tests/ --fix",
-    "postinstall": "npm run build-css"
+    "postinstall": "npm run build-css",
+    "build:frontend": "node scripts/build-frontend.js",
+    "watch:frontend": "node scripts/build-frontend.js --watch",
+    "dev:full": "concurrently \"npm run watch-css\" \"npm run watch:frontend\" \"npm run dev:ts\""
   },
   "dependencies": {
-    
     "cors": "^2.8.5",
     "dotenv": "^17.0.1",
     "express": "^4.18.2",
     "express-rate-limit": "^7.5.1",
     "node-cron": "^3.0.3",
-    
     "sqlite3": "^5.1.6",
     "swagger-jsdoc": "^6.2.8",
     "swagger-ui-express": "^5.0.1"
@@ -38,6 +39,7 @@
     "@types/cors": "^2.8.19",
     "@types/express": "^5.0.3",
     "@types/jest": "^30.0.0",
+    "@types/leaflet": "^1.9.19",
     "@types/node": "^24.0.10",
     "@types/node-cron": "^3.0.11",
     "@types/sqlite3": "^3.1.11",
@@ -47,6 +49,7 @@
     "@typescript-eslint/eslint-plugin": "^8.35.1",
     "@typescript-eslint/parser": "^8.35.1",
     "concurrently": "^9.2.0",
+    "esbuild": "^0.25.6",
     "eslint": "^9.30.1",
     "globals": "^16.3.0",
     "jest": "^29.7.0",