feat: Implement Share Modal for document sharing functionality

- Added ShareModal component to manage user and link sharing for documents.
- Created AuthContext to handle user authentication state and token management.
- Updated useYjsDocument hook to support sharing via tokens.
- Enhanced Yjs document creation to include user information and authentication tokens.
- Introduced AuthCallback page to handle authentication redirects and token processing.
- Modified EditorPage and KanbanPage to include share functionality.
- Created LoginPage with Google and GitHub authentication options.
- Added styles for LoginPage.
- Defined types for authentication and sharing in respective TypeScript files.

frontend/src/App.tsx

@@ -1,17 +1,46 @@
 import { BrowserRouter, Route, Routes } from "react-router-dom";
+import { AuthProvider } from "./contexts/AuthContext";
+import ProtectedRoute from "./components/ProtectedRoute";
+import LoginPage from "./pages/LoginPage";
+import AuthCallback from "./pages/AuthCallback";
 import EditorPage from "./pages/EditorPage.tsx";
 import Home from "./pages/Home.tsx";
 import KanbanPage from "./pages/KanbanPage.tsx";
 
 function App() {
   return (
-    <BrowserRouter>
-      <Routes>
-        <Route path="/" element={<Home />} />
-        <Route path="/editor/:id" element={<EditorPage />} />
-        <Route path="/kanban/:id" element={<KanbanPage />} />
-      </Routes>
-    </BrowserRouter>
+    <AuthProvider>
+      <BrowserRouter>
+        <Routes>
+          <Route path="/login" element={<LoginPage />} />
+          <Route path="/auth/callback" element={<AuthCallback />} />
+          <Route
+            path="/"
+            element={
+              <ProtectedRoute>
+                <Home />
+              </ProtectedRoute>
+            }
+          />
+          <Route
+            path="/editor/:id"
+            element={
+              <ProtectedRoute>
+                <EditorPage />
+              </ProtectedRoute>
+            }
+          />
+          <Route
+            path="/kanban/:id"
+            element={
+              <ProtectedRoute>
+                <KanbanPage />
+              </ProtectedRoute>
+            }
+          />
+        </Routes>
+      </BrowserRouter>
+    </AuthProvider>
   );
 }