Add Jellyfin OIDC provider, application and RBAC groups

Jellyfin moves to Authentik SSO via jellyfin-plugin-sso (OIDC), keeping
native clients on Jellyfin local/API auth. Adds the oauth2 provider and
application for jellyfin.k8s.syd1.au.unkin.net plus the akP permission
groups gating access, wired into the standard-user and global-admin
roles per the two-tier RBAC model.

- Adds providers_oauth2/jellyfin.yaml: confidential client, secret read
  from kv/kubernetes/namespace/jellyfin/default/oauth-credentials,
  redirect URIs for the SSO plugin callback paths
- Adds akP-jellyfin-admin and akP-jellyfin-user bound to the app
- Nests akP-jellyfin-user under akR-standard-user and
  akP-jellyfin-admin under akR-global-admin

config/permissions/akP-jellyfin-admin.yaml

@@ -0,0 +1,3 @@
+# Permission group akP-jellyfin-admin (name = filename). Grants admin
+# access to jellyfin: bound to the jellyfin application and mapped to its admin role.
+application: jellyfin

config/permissions/akP-jellyfin-user.yaml

@@ -0,0 +1,3 @@
+# Permission group akP-jellyfin-user (name = filename). Grants user
+# access to jellyfin: bound to the jellyfin application and mapped to its user role.
+application: jellyfin

config/providers_oauth2/jellyfin.yaml

@@ -0,0 +1,29 @@
+# OAuth2/OIDC provider + application for Jellyfin
+# (jellyfin.k8s.syd1.au.unkin.net), consumed by jellyfin-plugin-sso (OIDC) so
+# the web UI signs in via Authentik while native clients keep Jellyfin local/API
+# auth. client_secret is read from Vault, not committed. The plugin requests the
+# `ak_groups` scope and matches the hierarchical groups claim against
+# akP-jellyfin-admin / akP-jellyfin-user for its admin/user role mapping, so no
+# role_mappings claim is needed here. The path segment "authentik" is the SSO
+# provider name configured in the plugin — it must match on the Jellyfin side.
+name: Jellyfin
+authorization_flow: default-provider-authorization-implicit-consent
+invalidation_flow: default-provider-invalidation-flow
+client_type: confidential
+client_id: jellyfin
+# Explicit dashboard tile launch URL (the Jellyfin web UI).
+launch_url: https://jellyfin.k8s.syd1.au.unkin.net/
+client_secret_vault:
+  mount: kv
+  path: kubernetes/namespace/jellyfin/default/oauth-credentials
+scope_mappings:
+  - goauthentik.io/providers/oauth2/scope-openid
+  - goauthentik.io/providers/oauth2/scope-email
+  - goauthentik.io/providers/oauth2/scope-profile
+redirect_uris:
+  # jellyfin-plugin-sso OIDC callback (plugin >= 3.5.2).
+  - matching_mode: strict
+    url: https://jellyfin.k8s.syd1.au.unkin.net/sso/OID/redirect/authentik
+  # Legacy plugin callback path, kept so older plugin builds also work.
+  - matching_mode: strict
+    url: https://jellyfin.k8s.syd1.au.unkin.net/sso/OID/r/authentik

config/roles/akR-global-admin.yaml

@@ -4,6 +4,7 @@ permissions:
   - akP-argocd-admin
   - akP-rancher-admin
   - akP-litellm-admin
+  - akP-jellyfin-admin
   # arrstack has no admin tier (it is a proxy front door); grant global admins
   # the front door plus every per-app entitlement so they reach all media apps.
   - akP-arrstack-user

config/roles/akR-standard-user.yaml

@@ -4,3 +4,4 @@ permissions:
   - akP-argocd-user
   - akP-rancher-user
   - akP-litellm-user
+  - akP-jellyfin-user