Refactor: Implement database queue infrastructure

supabase/migrations/20251006143346_04773712-d383-41d7-ac83-4d48a428ef83.sql

@@ -0,0 +1,27 @@
+-- Create moderation queue in pgmq
+SELECT pgmq.create('moderation_queue');
+
+-- Add queue management columns to content_submissions
+ALTER TABLE content_submissions 
+ADD COLUMN IF NOT EXISTS priority INTEGER NOT NULL DEFAULT 3,
+ADD COLUMN IF NOT EXISTS assigned_to UUID REFERENCES auth.users(id),
+ADD COLUMN IF NOT EXISTS assigned_at TIMESTAMP WITH TIME ZONE,
+ADD COLUMN IF NOT EXISTS locked_until TIMESTAMP WITH TIME ZONE,
+ADD COLUMN IF NOT EXISTS submitted_at TIMESTAMP WITH TIME ZONE NOT NULL DEFAULT NOW(),
+ADD COLUMN IF NOT EXISTS first_reviewed_at TIMESTAMP WITH TIME ZONE,
+ADD COLUMN IF NOT EXISTS resolved_at TIMESTAMP WITH TIME ZONE,
+ADD COLUMN IF NOT EXISTS review_count INTEGER DEFAULT 0;
+
+-- Create indexes for queue operations
+CREATE INDEX IF NOT EXISTS idx_submissions_queue_status 
+  ON content_submissions(status, priority DESC, submitted_at ASC) 
+  WHERE status IN ('pending', 'partially_approved');
+
+CREATE INDEX IF NOT EXISTS idx_submissions_assigned 
+  ON content_submissions(assigned_to, locked_until) 
+  WHERE assigned_to IS NOT NULL;
+
+-- Simple index on locked_until for expired lock cleanup
+CREATE INDEX IF NOT EXISTS idx_submissions_locked_until 
+  ON content_submissions(locked_until) 
+  WHERE locked_until IS NOT NULL;