refactor(routing): Migrate to React Router and simplify component structure

Replaces 'wouter' with 'react-router-dom' to standardize the routing library and resolve dependency conflicts.

Key changes:

- All routing logic, including hooks (useLocation) and components (Link, Routes), now uses 'react-router-dom'.

- The component tree has been simplified by removing the MainContainer component and moving its layout directly into App.tsx.

- The <BrowserRouter> provider is now correctly placed at the application's entry point in main.tsx.

package.json

@@ -19,9 +19,9 @@
     "lucide-react": "^0.544.0",
     "react": "^19.1.1",
     "react-dom": "^19.1.1",
+    "react-router-dom": "^7.9.1",
     "tailwind-merge": "^3.3.1",
     "tailwindcss": "^4.1.13",
-    "wouter": "^3.7.1",
     "zustand": "^5.0.8"
   },
   "devDependencies": {
@@ -29,6 +29,7 @@
     "@types/node": "^24.3.1",
     "@types/react": "^19.1.10",
     "@types/react-dom": "^19.1.7",
+    "@types/react-router-dom": "^5.3.3",
     "@vitejs/plugin-react-swc": "^4.1.0",
     "eslint": "^9.33.0",
     "eslint-plugin-react-hooks": "^5.2.0",