Fix: Correct ban migration logic

supabase/migrations/20251030120117_ba8dcb4e-b12c-4f86-9a71-61e752a280ca.sql

@@ -0,0 +1,23 @@
+-- Add ban expiration tracking
+ALTER TABLE public.profiles 
+ADD COLUMN IF NOT EXISTS ban_expires_at timestamptz;
+
+COMMENT ON COLUMN public.profiles.ban_expires_at IS 
+'When the ban expires (null = permanent ban). Automatic unbanning is handled by a scheduled edge function.';
+
+-- Update existing banned users to have a default ban reason
+UPDATE public.profiles
+SET ban_reason = 'No reason provided (legacy ban)'
+WHERE banned = true AND (ban_reason IS NULL OR ban_reason = '');
+
+-- Add constraint to require ban_reason when banned
+ALTER TABLE public.profiles 
+ADD CONSTRAINT ban_reason_required 
+CHECK (
+  (banned = true AND ban_reason IS NOT NULL AND ban_reason != '') 
+  OR 
+  (banned = false)
+);
+
+COMMENT ON CONSTRAINT ban_reason_required ON public.profiles IS 
+'Ensures that a ban reason must be provided when banning a user';