fix: UserContext fast-path initialization — no spinner on page refresh

Before: UserContext waited for a Supabase profiles table query (~200ms)
before setting isInitialized=true, causing FullContextRoutes to show
a spinner on every page refresh even with a valid stored session.

After: UserContext immediately builds a profile from auth metadata +
localStorage (synchronous, zero network calls) and sets isInitialized=true
before the Supabase query. The Supabase profiles table is still queried
in the background and the profile is updated when it returns with
authoritative user_db_name/school_db_name data.

On refresh with a stored session: auth metadata is available
synchronously via INITIAL_SESSION, so the page renders with no visible
spinner.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

src/contexts/UserContext.tsx

@@ -112,73 +112,59 @@ export const UserProvider = ({ children }: { children: React.ReactNode }) => {
 
      let profileRow: Record<string, unknown> | null = null;
 
-      logger.debug('user-context', '🔧 Step 5: Querying profiles table...', {
+      // Fast-path: build profile from auth metadata + localStorage immediately.
-        userId: userInfo.id
+      // This clears the spinner before any network call so the page renders on refresh
+      // without waiting for the Supabase profiles query (~200ms).
+      const fastMetadata = userInfo.user_metadata as CCUserMetadata;
+      const fastStoredUserDb = DatabaseNameService.getStoredUserDatabase();
+      const fastStoredSchoolDb = DatabaseNameService.getStoredSchoolDatabase();
+      const fastUserDb = fastStoredUserDb || DatabaseNameService.getUserPrivateDB(fastMetadata?.user_type || '', userInfo.id);
+      const fastProfile: CCUser = {
+        id: userInfo.id,
+        email: userInfo.email,
+        user_type: fastMetadata?.user_type || '',
+        username: fastMetadata?.username || userInfo.email?.split('@')[0] || 'user',
+        display_name: String(fastMetadata?.display_name || ''),
+        user_db_name: String(fastUserDb || ''),
+        school_db_name: String(fastStoredSchoolDb || ''),
+        created_at: userInfo.created_at,
+        updated_at: userInfo.updated_at
+      };
+      DatabaseNameService.rememberDatabaseNames({
+        userDbName: fastProfile.user_db_name,
+        schoolDbName: fastProfile.school_db_name
       });
-      
+      if (mountedRef.current && !isInitialized) {
-      // Set loading state when we start the actual database query
+        setProfile(fastProfile);
-      setLoading(true);
+        setLoading(false);
-      
+        setIsInitialized(true);
-      // Query profiles table without timeout to see actual error
+        logger.debug('user-context', '⚡ Fast-path: profile initialized from auth metadata, no spinner');
-      logger.debug('user-context', '🔧 Step 5b: Starting profiles query...', {
+      }
-        userId: userInfo.id,
+
-        clientType: 'authenticated'
+      // Background: query Supabase profiles for authoritative data (user_db_name, school_db_name, display_name).
-      });
+      // No setLoading toggles — spinner is already cleared above.
-      
-      logger.debug('user-context', '🔧 Step 5b1: About to make profiles query...', {
-        userId: userInfo.id,
-        queryStarted: true
-      });
-      
       const { data, error } = await supabase
         .from('profiles')
         .select('*')
         .eq('id', userInfo.id)
         .single();
-      
-      logger.debug('user-context', '🔧 Step 5b2: Direct fetch completed...', {
-        userId: userInfo.id,
-        hasData: !!data,
-        hasError: !!error
-      });
-      
-      logger.debug('user-context', '🔧 Step 5c: Profiles query completed', {
-        hasData: !!data,
-        hasError: !!error,
-        errorCode: error?.code,
-        errorMessage: error?.message
-      });
-      
-      logger.debug('user-context', '🔧 Step 5a: Profiles query result', {
-        hasData: !!data,
-        hasError: !!error,
-        errorCode: error?.code,
-        errorMessage: error?.message
-      });
 
       if (error && error.code !== 'PGRST116') {
-        logger.warn('user-context', '⚠️ Profiles query failed, using fallback', {
+        logger.warn('user-context', '⚠️ Profiles query failed, using fast-path profile', {
           error: error.message,
           code: error.code
         });
-        // Don't throw error, just use fallback profile
         profileRow = null;
       } else if (data) {
         profileRow = data;
-        logger.debug('user-context', '✅ Found profile data in database', {
+        logger.debug('user-context', '✅ Supabase profile fetched', {
           userId: data.id,
-          userType: data.user_type,
           userDbName: data.user_db_name
         });
       } else {
-        logger.debug('user-context', '⚠️ No profile data found - will create default');
         profileRow = null;
       }
 
-      // Clear loading state after profiles query completes
-      setLoading(false);
-      logger.debug('user-context', '🔧 Step 5d: Loading state cleared');
-
       logger.debug('user-context', '🔧 Step 6: Processing profile data...', {
         userId: userInfo.id,
         hasProfileRow: !!profileRow,