Implement unban functionality

supabase/migrations/20251030015243_5e033e34-37ab-41cd-8f41-8a405c34552a.sql

@@ -0,0 +1,37 @@
+-- Enhance invalidate_banned_user_sessions trigger to handle both ban and unban events
+CREATE OR REPLACE FUNCTION public.invalidate_banned_user_sessions()
+RETURNS TRIGGER
+LANGUAGE plpgsql
+SECURITY DEFINER
+SET search_path = public
+AS $$
+BEGIN
+  -- If user was just banned (banned changed from false to true)
+  IF NEW.banned = true AND OLD.banned = false THEN
+    PERFORM pg_notify(
+      'user_banned',
+      json_build_object(
+        'user_id', NEW.user_id,
+        'username', NEW.username,
+        'banned_at', NOW(),
+        'action', 'banned'
+      )::text
+    );
+  END IF;
+  
+  -- If user was just unbanned (banned changed from true to false)
+  IF NEW.banned = false AND OLD.banned = true THEN
+    PERFORM pg_notify(
+      'user_unbanned',
+      json_build_object(
+        'user_id', NEW.user_id,
+        'username', NEW.username,
+        'unbanned_at', NOW(),
+        'action', 'unbanned'
+      )::text
+    );
+  END IF;
+  
+  RETURN NEW;
+END;
+$$;