feat: migrate frontend from Vue 3 to React 18 with TanStack ecosystem

- Complete rewrite of frontend using React 18 + TypeScript in strict mode
- Implement TanStack Router for file-based routing matching URL structure
- Use TanStack Query for server state management with smart caching
- Replace Pinia stores with React Context API for auth and UI state
- Adopt Tailwind CSS + shadcn/ui components for consistent styling
- Switch from pnpm to Bun for faster package management and builds
- Configure Vite to support React, TypeScript, and modern tooling
- Create frontend.go with Go embed package for embedding dist/ in binary
- Implement comprehensive TypeScript interfaces (strict mode, no 'any' types)
- Add dark mode support throughout with Tailwind CSS dark: classes
- Set up i18n infrastructure (English translations included)
- Remove all Vue 3 code, components, stores, CSS, and assets
- Includes 18 new files with ~2000 lines of production-ready code

frontend/tsconfig.json

@@ -1,11 +1,34 @@
 {
-  "files": [],
-  "references": [
-    {
-      "path": "./tsconfig.node.json"
+  "compilerOptions": {
+    "target": "ES2020",
+    "useDefineForClassFields": true,
+    "lib": ["ES2020", "DOM", "DOM.Iterable"],
+    "module": "ESNext",
+    "skipLibCheck": true,
+    "esModuleInterop": true,
+    "allowSyntheticDefaultImports": true,
+
+    /* Bundler mode */
+    "moduleResolution": "bundler",
+    "allowImportingTsExtensions": true,
+    "resolveJsonModule": true,
+    "isolatedModules": true,
+    "noEmit": true,
+    "jsx": "react-jsx",
+
+    /* Path aliases */
+    "baseUrl": ".",
+    "paths": {
+      "@/*": ["src/*"]
     },
-    {
-      "path": "./tsconfig.app.json"
-    }
-  ]
+
+    /* Strict type checking */
+    "strict": true,
+    "noUnusedLocals": true,
+    "noUnusedParameters": true,
+    "noFallthroughCasesInSwitch": true,
+    "forceConsistentCasingInFileNames": true
+  },
+  "include": ["src"],
+  "references": [{ "path": "./tsconfig.node.json" }]
 }