authentik: add InfisicalStaticSecret for authentik-secrets (centralize SSO secret)

Out-of-band Secret -> Infisical homelab/prod /authentik. Parallel-name target
authentik-secrets-infisical (Owner), passthrough of the 2 LIVE keys
(AUTHENTIK_SECRET_KEY, POSTGRES_PASSWORD). The dead orphan key
AUTHENTIK_POSTGRESQL__PASSWORD is intentionally dropped. Old secret stays live
until decommission. Applied via kubectl (not ArgoCD-managed).

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

authentik/infisical-authentik-secrets.yaml

@@ -0,0 +1,31 @@
+apiVersion: secrets.infisical.com/v1beta1
+kind: InfisicalStaticSecret
+metadata:
+  name: authentik-secrets
+  namespace: authentik
+spec:
+  # Shared, read-only machine identity (no write grant, no PushSecret).
+  # Source is the /authentik folder, 2 live keys:
+  #   AUTHENTIK_SECRET_KEY  - authentik's crypto root (signs sessions/cookies,
+  #                           encrypts sensitive DB fields); lifted byte-identical.
+  #   POSTGRES_PASSWORD     - the SINGLE DB-password key; feeds BOTH postgres
+  #                           (env POSTGRES_PASSWORD) AND server/worker
+  #                           (env AUTHENTIK_POSTGRESQL__PASSWORD) -> cannot drift.
+  # The old secret's dead 3rd key (AUTHENTIK_POSTGRESQL__PASSWORD, orphan) is
+  # intentionally NOT carried; it retires when the old secret is deleted.
+  # Consumer secretKeyRef.key values already match these names -> passthrough.
+  infisicalAuthRef:
+    name: infisical-auth
+    namespace: infisical-operator
+  sources:
+    - projectId: 17e98e9d-70f5-43d1-8382-7da818dfcdd0   # project "homelab"
+      environmentSlug: prod
+      secretPath: /authentik
+  syncOptions:
+    refreshInterval: 60s
+  targets:
+    - kind: Secret
+      name: authentik-secrets-infisical    # parallel name — old secret stays live until 3c
+      namespace: authentik
+      creationPolicy: Owner
+      # key passthrough: synced Secret carries AUTHENTIK_SECRET_KEY, POSTGRES_PASSWORD verbatim