feat: deploy Immich with Authentik OIDC, rock as admin

Self-hosted photo backup (Google Photos replacement) - raw manifests,
no Helm chart, self-contained under k8s/apps/immich including its own
CNPG Postgres. Media PVC shares the cp-3 HDD 2TB/2TB with
paperless-media.

Postgres is pg18, not this repo's usual 16.2: CNPG's official pgvector
extension image (ghcr.io/cloudnative-pg/pgvector) is only published
for pg18, loaded via CNPG's ImageVolume extension mechanism (operator
1.30.0 / k8s 1.36.1 both support it). Immich auto-manages CREATE
EXTENSION itself at startup.

OIDC via a new "immich_role" Authentik scope mapping (homelab-admins/
immich-admins -> "admin" claim, else "user"), consumed by Immich's
OAuth roleClaim setting which re-syncs isAdmin on every login - more
reliable than Immich's racy first-user-is-admin fallback. Config
composed into an immich-oidc Secret and mounted as IMMICH_CONFIG_FILE,
matching the paperless-oidc pattern. k8s RBAC (immich-operator Role +
oidc:immich-admins binding) mirrors paperless/rbac.yaml.

immich namespace pre-created in k8s/infra/databases/namespaces.yaml
(not just immich's own CreateNamespace=true) since the iam PostSync
job's RoleBinding needs it to exist before wave 8.

k8s/argocd/apps/60-applications.yaml

@@ -170,6 +170,38 @@ spec:
     syncOptions:
       - CreateNamespace=true
 ---
+# Photo/video backup. Self-contained (unlike paperless, its CNPG Postgres
+# lives here too, not in k8s/infra/databases) - CreateNamespace=true creates
+# the namespace before any manifest in this Application applies, including
+# the Cluster CR, so no separate wave-2 pre-creation step is needed. Postgres
+# is pg18 (not this repo's usual 16.2) because CNPG's official pgvector
+# extension image only publishes pg18 builds - see k8s/apps/immich/db.yaml.
+# media PVC shares the cp-3 HDD 2TB/2TB with paperless-media. OIDC via
+# Authentik provisioned by k8s/infra/iam's PostSync job (immich entry in
+# SERVICES + immich_role scope mapping for admin-via-claim).
+apiVersion: argoproj.io/v1alpha1
+kind: Application
+metadata:
+  name: immich
+  namespace: argocd
+  annotations:
+    argocd.argoproj.io/sync-wave: "8"
+spec:
+  project: homelab
+  source:
+    repoURL: https://forgejo.riotpiao.com/rock/homelab.git
+    targetRevision: main
+    path: k8s/apps/immich
+  destination:
+    server: https://kubernetes.default.svc
+    namespace: immich
+  syncPolicy:
+    automated:
+      prune: true
+      selfHeal: true
+    syncOptions:
+      - CreateNamespace=true
+---
 # Consolidated: homarr + homarr-patches → homarr
 # Helm chart + values + PostSync hook patch (fix-probes-job.yaml)
 apiVersion: argoproj.io/v1alpha1