Improve moderation edge flow and timeout handling

- Add early logging and health check to process-selective-approval edge function
- Implement idempotency check with timeout to avoid edge timeouts
- Expose health endpoint for connectivity diagnostics
- Increase client moderation action timeout from 30s to 60s
- Update moderation actions hook to accommodate longer timeouts

supabase/functions/process-selective-approval/index.ts

@@ -16,11 +16,42 @@ import { ValidationError } from '../_shared/typeValidation.ts';
 const handler = async (req: Request, context: { supabase: any; user: any; span: any; requestId: string }) => {
   const { supabase, user, span: rootSpan, requestId } = context;
 
+  // Early logging - confirms request reached handler
+  addSpanEvent(rootSpan, 'handler_entry', { 
+    requestId, 
+    userId: user.id,
+    timestamp: Date.now() 
+  });
+
   setSpanAttributes(rootSpan, { 
     'user.id': user.id,
     'function.name': 'process-selective-approval' 
   });
 
+  // Health check endpoint
+  if (req.url.includes('/health')) {
+    addSpanEvent(rootSpan, 'health_check_start');
+    const { data, error } = await supabase
+      .from('content_submissions')
+      .select('count')
+      .limit(1);
+    
+    addSpanEvent(rootSpan, 'health_check_complete', { 
+      dbConnected: !error,
+      error: error?.message 
+    });
+
+    return new Response(JSON.stringify({ 
+      status: 'ok', 
+      dbConnected: !error,
+      timestamp: Date.now(),
+      error: error?.message
+    }), { 
+      headers: { 'Content-Type': 'application/json' },
+      status: error ? 500 : 200
+    });
+  }
+
   // STEP 1: Parse and validate request
   addSpanEvent(rootSpan, 'validation_start');
   
@@ -57,14 +88,37 @@ const handler = async (req: Request, context: { supabase: any; user: any; span:
   });
   addSpanEvent(rootSpan, 'validation_complete');
 
-  // STEP 2: Idempotency check
+  // STEP 2: Idempotency check with timeout
   addSpanEvent(rootSpan, 'idempotency_check_start');
-  const { data: existingKey } = await supabase
+  
+  const idempotencyCheckPromise = supabase
     .from('submission_idempotency_keys')
     .select('*')
     .eq('idempotency_key', idempotencyKey)
     .single();
 
+  // Add 5 second timeout for idempotency check
+  const timeoutPromise = new Promise((_, reject) => 
+    setTimeout(() => reject(new Error('Idempotency check timed out after 5s')), 5000)
+  );
+
+  let existingKey;
+  try {
+    const result = await Promise.race([
+      idempotencyCheckPromise,
+      timeoutPromise
+    ]) as any;
+    existingKey = result.data;
+  } catch (timeoutError: any) {
+    addSpanEvent(rootSpan, 'idempotency_check_timeout', { error: timeoutError.message });
+    throw new Error(`Database query timeout: ${timeoutError.message}`);
+  }
+  
+  addSpanEvent(rootSpan, 'idempotency_check_complete', { 
+    foundKey: !!existingKey,
+    status: existingKey?.status 
+  });
+
   if (existingKey?.status === 'completed') {
     addSpanEvent(rootSpan, 'idempotency_cache_hit');
     setSpanAttributes(rootSpan, { 'cache.hit': true });