fix(realtime): domainRealtime CHANNEL_ERROR — wrong filter column + missing publication

Two bugs caused the domainRealtime channel to fail with CHANNEL_ERROR and
reconnect-loop every 3s (which also dragged down the notifRealtime channel via
the shared websocket close):
  1. useDomainSubmissionRealtime.ts filtered domain_submissions on a column that
     doesn't exist (`submitter_id`) — the actual column is `user_id`. Postgres
     raised on the publication-side filter registration → CHANNEL_ERROR.
  2. rebreak.user_custom_domains was never added to the supabase_realtime
     publication — the channel also subscribes to that table. New migration
     20260511_fix_realtime_user_custom_domains adds it.

(Diagnosis via backyard agent against the self-hosted Supabase on the Hetzner box.)

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

apps/rebreak-native/hooks/useDomainSubmissionRealtime.ts

@@ -37,7 +37,7 @@ export function useDomainSubmissionRealtime(
             event: "*",
             schema: "rebreak",
             table: "domain_submissions",
-            filter: `submitter_id=eq.${myId}`,
+            filter: `user_id=eq.${myId}`,
           },
           () => onChange(),
         )

backend/prisma/migrations/20260511_fix_realtime_user_custom_domains/migration.sql

@@ -0,0 +1,9 @@
+-- Enable Supabase Realtime for user_custom_domains table.
+-- Fixes the remaining CHANNEL_ERROR in the domainRealtime subscription:
+-- useDomainSubmissionRealtime.ts subscribes to rebreak.user_custom_domains, but
+-- that table was never added to the supabase_realtime publication — so the whole
+-- channel (which also covers domain_submissions + notifications) failed with
+-- CHANNEL_ERROR and reconnect-looped every 3s.
+-- (Companion fix in the RN code: the domain_submissions filter used a non-existent
+-- column `submitter_id` — corrected to `user_id`.)
+ALTER PUBLICATION supabase_realtime ADD TABLE rebreak.user_custom_domains;