feat(compose): use one secret bundle for local services

scripts/test-vector-backup-restore-safety.sh

@@ -88,6 +88,13 @@ grep -q -- '--exit-on-error' "$tmp/restore.log"
 
 # The live restore smoke must follow the packaged migration set instead of a stale
 # hard-coded count when a new migration is added.
+if grep -Eq 'vector_(bootstrap|migrator|reader|writer)_password' \
+    deploy/compose.local-vector.yaml deploy/compose.preprocess-local-vector.yaml; then
+  echo "local-vector Compose still declares legacy per-password secrets" >&2
+  exit 1
+fi
+grep -Fq 'thothii_secrets' deploy/compose.local-vector.yaml
+grep -Fq 'thothii_secrets' deploy/compose.preprocess-local-vector.yaml
 if grep -Fq 'SELECT count(*) = 3 FROM public.tht_vector_migrations' \
     scripts/local-vector-smoke.sh; then
   echo "local vector smoke hard-codes the pre-004 migration count" >&2