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/package.json

@@ -10,6 +10,9 @@
     "preview": "vite preview"
   },
   "dependencies": {
+    "@dnd-kit/core": "^6.3.1",
+    "@dnd-kit/sortable": "^10.0.0",
+    "@dnd-kit/utilities": "^3.2.2",
     "@tiptap/extension-collaboration": "^2.27.1",
     "@tiptap/extension-collaboration-cursor": "^2.26.2",
     "@tiptap/pm": "^2.27.1",