[management] resolve private services on custom domains in synthesized DNS zones (#6348)

private services on a custom domain didn't resolve on clients — the synthesized DNS zone was anchored to the cluster, and the account's custom domains weren't even
  loaded.

- account.go — SynthesizePrivateServiceZones now keys zones by a resolved apex (privateServiceDomainZone): cluster suffix → registered account.Domains (filtered by matching
  TargetCluster, longest wins) → skip if none. One zone per apex; custom-domain services group under their registered domain.
- sql_store.go — GetAccount now loads account.Domains on both loaders (gorm Preload("Domains") + pgx goroutine via ListCustomDomains; errChan buffer bumped 12→16). This was
  the reason the deploy didn't work — the relation was empty in prod.
- Tests — custom-domain zone synthesis cases (apex resolution, free+custom separation, sibling collapse, cluster mismatch, mixed cluster/custom/public) + GetAccount
  domain-preload tests on sqlite and Postgres.

.github/workflows/release.yml

@@ -29,10 +29,10 @@ jobs:
           persist-credentials: false
 
       - name: Generate FreeBSD port diff
-        run: bash release_files/freebsd-port-diff.sh
+        run: bash -x release_files/freebsd-port-diff.sh
 
       - name: Generate FreeBSD port issue body
-        run: bash release_files/freebsd-port-issue-body.sh
+        run: bash -x release_files/freebsd-port-issue-body.sh
 
       - name: Check if diff was generated
         id: check_diff