Add SuperTokens authentication integration

- Install supertokens-auth-react, supertokens-node, supertokens-web-js
- Create frontend and backend SuperTokens configuration
- Add API route handler for auth endpoints
- Add SuperTokensProvider wrapper in root layout
- Create new auth component with SuperTokens UI
- Configure Google and GitHub OAuth providers
- Ready for SuperTokens core deployment

Co-authored-by: Cursor <cursoragent@cursor.com>

package.json

@@ -46,6 +46,9 @@
     "react": "^19.2.4",
     "react-dom": "^19.2.4",
     "sonner": "^2.0.7",
+    "supertokens-auth-react": "^0.51.2",
+    "supertokens-node": "^24.0.1",
+    "supertokens-web-js": "^0.16.0",
     "tailwind-merge": "^3.4.0",
     "tsx": "^4.20.6",
     "uuid": "^13.0.0",