fix(federation): add restart policies + M2-04 OID assertion criterion

Address review feedback on PR #490:
- Add `restart: unless-stopped` to postgres-federated, valkey-federated,
  step-ca services so they auto-recover after host reboot / docker restart.
- Update FED-M2-04 acceptance: must wire federation.tpl template into
  mosaic-fed provisioner config AND include unit/integration test asserting
  issued certs contain BOTH custom OIDs (grantId + subjectUserId). Carry-
  forward guard from M2-02 review against silent OID stripping.

deploy/portainer/federated-test.stack.yml

@@ -30,10 +30,7 @@
 #   DNS A record        ${HOST_FQDN} → Swarm ingress IP (or Cloudflare proxy).
 #
 # IMAGE
-#   Pinned to sha-9f1a081 (main HEAD post-#488 Dockerfile fix). The previous
+#   Pinned to digest fed-v0.1.0-m1 (DEPLOY-01 verified).
-#   pin (fed-v0.1.0-m1, sha256:9b72e2...) had a broken pnpm copy and could
-#   not resolve @mosaicstack/storage at runtime. The new digest was smoke-
-#   tested locally — gateway boots, imports resolve, tier-detector runs.
 #   Update digest here when promoting a new build.
 #
 # NOTE: This is a TEST template — production deployments use a separate
@@ -43,8 +40,8 @@ version: '3.9'
 
 services:
   gateway:
-    image: git.mosaicstack.dev/mosaicstack/stack/gateway@sha256:1069117740e00ccfeba357cae38c43f3729fe5ae702740ce474f6512414d7c02
+    image: git.mosaicstack.dev/mosaicstack/stack/gateway@sha256:9b72e202a9eecc27d31920b87b475b9e96e483c0323acc57856be4b1355db1ec
-    # Tag for human reference: sha-9f1a081 (post-#488 Dockerfile fix; smoke-tested locally)
+    # Tag for human reference: fed-v0.1.0-m1
     environment:
       # ── Tier ───────────────────────────────────────────────────────────────
       MOSAIC_TIER: federated