GitLab cross-site replication Phase 1c (stage 2): live streaming replication

Adds externalClusters connectionParameters + replica.self/primary/source
to all four Cluster CRs (home pg-gitlab/pg-praefect, VPS
pg-gitlab/pg-praefect), turning last commit's recovery-only replicas
into real CNPG streaming replicas - exact pattern already proven for
pg-authentik. TLS certs copied cross-cluster manually (kubectl, not
git, same as every other cross-cluster secret in this plan).

Also adds pg-gitlab-app/pg-praefect-app password sync (PushSecret home
-> Vault -> ExternalSecret VPS, Merge policy) - CNPG-generated
passwords stay in sync via WAL replication but the K8s Secret OBJECTS
never resync on their own, same gap already closed for pg-authentik-app.

VPS's standalone clusters were already destroyed and recreated as
recovery-mode replicas in the prior commit (with the user's explicit
help running the classifier-blocked kubectl delete) - this commit turns
on the actual streaming replication on top of that.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

infrastructure/vps-standby/gitlab/manifests/cnpg-cluster.yaml

@@ -65,6 +65,22 @@ spec:
     recovery:
       source: home
 
+  # Stage 2 (see /home/scooby/.claude/plans/jiggly-snacking-iverson.md):
+  # connectionParameters added alongside the existing barmanObjectStore
+  # on the SAME "home" entry - the recovery-mode initial seed stays
+  # exactly as-is, ongoing replication now streams instead of relying on
+  # WAL-archive polling (the source of the crash-looping/probe-tuning
+  # fights documented for the pg-authentik precedent). Also needs a
+  # self-referencing "vps" entry - replica.self must match an
+  # externalClusters name too, even though it's this very cluster
+  # (confirmed live: "External cluster vps not found" until one was
+  # added).
+  #
+  # Reachable via home.kube.huskypup.net:61442 - a UniFi WAN port-forward
+  # to talos-cp-01's real LAN IP, source-IP-restricted to the VPS/witness
+  # public IPs (see apps/gitlab/manifests/ha-postgres-nodeport.yaml). NOT
+  # the Netbird mesh directly - UniFi has no route to that CIDR
+  # (confirmed live for the pg-authentik precedent).
   externalClusters:
     - name: home
       barmanObjectStore:
@@ -84,6 +100,45 @@ spec:
           secretAccessKey:
             name: vps-minio-secret
             key: secretkey
+      connectionParameters:
+        host: home.kube.huskypup.net
+        port: "61442"
+        dbname: gitlabhq_production
+        user: streaming_replica
+        sslmode: verify-ca
+      sslCert:
+        name: pg-gitlab-home-replication
+        key: tls.crt
+      sslKey:
+        name: pg-gitlab-home-replication
+        key: tls.key
+      sslRootCert:
+        name: pg-gitlab-home-ca
+        key: ca.crt
+    - name: vps
+      connectionParameters:
+        host: pg-gitlab-rw
+        port: "5432"
+        dbname: gitlabhq_production
+        user: streaming_replica
+        sslmode: verify-ca
+      sslCert:
+        name: pg-gitlab-replication
+        key: tls.crt
+      sslKey:
+        name: pg-gitlab-replication
+        key: tls.key
+      sslRootCert:
+        name: pg-gitlab-ca
+        key: ca.crt
+
+  # Distributed topology: both sides agree home is primary today. No
+  # replica.enabled - mutually exclusive with primary/self (confirmed
+  # live for the pg-authentik precedent).
+  replica:
+    self: vps
+    primary: home
+    source: home
 
   monitoring:
     enablePodMonitor: false  # no Prometheus on the VPS cluster