Migrate backend from Lovable Cloud to own Supabase (EDU project)

- Point .env + supabase/config.toml at EDU (qgmcpounpkgsjlwosjdi)
- Replace Lovable Google-OAuth shim with native supabase.auth.signInWithOAuth
- Remove src/integrations/lovable and @lovable.dev/cloud-auth-js dependency
- Drop .lovable metadata; gitignore supabase/.temp

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

src/routeTree.gen.ts

@@ -307,3 +307,13 @@ const rootRouteChildren: RootRouteChildren = {
 export const routeTree = rootRouteImport
   ._addFileChildren(rootRouteChildren)
   ._addFileTypes<FileRouteTypes>()
+
+import type { getRouter } from './router.tsx'
+import type { startInstance } from './start.ts'
+declare module '@tanstack/react-start' {
+  interface Register {
+    ssr: true
+    router: Awaited<ReturnType<typeof getRouter>>
+    config: Awaited<ReturnType<typeof startInstance.getOptions>>
+  }
+}