paperless: gate every hostname behind authentik forward-auth

Add nginx auth_request annotations to the paperless ingress and a
matching forward_domain ProxyProvider + Application in the Authentik
blueprint, attached to the embedded outpost. cookie_domain=renner.uno
shares the session across all four paperless aliases (paperless.* and
docs.*, both .renner.uno and .k.renner.uno).

Also drop the half-built `Caddy docs.renner.uno` provider that was
producing a phantom ak-outpost-caddy ingress conflicting with the
paperless ingress on docs.renner.uno.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

kubernetes/apps/authentik/blueprints-configmap.yaml

@@ -25,12 +25,54 @@ data:
         attrs:
           local: true
 
+      # forward_domain provider for paperless. external_host points at
+      # the embedded outpost's public URL (where unauthenticated users
+      # are redirected to sign in). cookie_domain=renner.uno makes the
+      # session cookie shared across every *.renner.uno and
+      # *.k.renner.uno host, so all four paperless aliases use the same
+      # login. Ingress-side annotations on the paperless Ingress wire
+      # nginx auth_request to this outpost.
+      - id: paperless-provider
+        model: authentik_providers_proxy.proxyprovider
+        identifiers:
+          name: paperless
+        state: present
+        attrs:
+          authorization_flow: !Find [authentik_flows.flow, [slug, default-provider-authorization-implicit-consent]]
+          invalidation_flow: !Find [authentik_flows.flow, [slug, default-provider-invalidation-flow]]
+          mode: forward_domain
+          external_host: https://auth.renner.uno
+          cookie_domain: renner.uno
+          access_token_validity: hours=24
+          refresh_token_validity: days=30
+          intercept_header_auth: true
+
+      - model: authentik_core.application
+        identifiers:
+          slug: paperless
+        state: present
+        attrs:
+          name: Paperless
+          slug: paperless
+          provider: !KeyOf paperless-provider
+          meta_launch_url: https://paperless.renner.uno
+          meta_description: "Paperless-ngx document management"
+
       - model: authentik_outposts.outpost
         identifiers:
           name: authentik Embedded Outpost
         state: present
         attrs:
           service_connection: !KeyOf k8s-conn
+          # Forward-auth providers attached here are served by the
+          # embedded outpost on auth.renner.uno (and via the in-cluster
+          # authentik-server Service for nginx auth_request). Setting
+          # `providers` is authoritative — anything attached to the
+          # embedded outpost via the UI that is not listed here will be
+          # detached on reconcile. Add new gated apps to this list, not
+          # the UI.
+          providers:
+            - !KeyOf paperless-provider
 
       # `Caddy` and `Local Radius` carried `kubernetes_namespace: default`
       # in their config from the Proxmox-era data, which the chart Role
@@ -124,3 +166,14 @@ data:
         identifiers:
           name: Local Docker connection
         state: absent
+
+      # The previous UI-managed proxy provider for docs.renner.uno was
+      # half-built (forward_single mode with no internal_host) and only
+      # ever produced a phantom ingress that conflicted with paperless's
+      # claim on the same hostname. Drop it so Authentik tears down the
+      # auto-generated ak-outpost-caddy ingress; paperless now owns the
+      # docs.* aliases and is gated by the paperless provider above.
+      - model: authentik_providers_proxy.proxyprovider
+        identifiers:
+          name: Caddy docs.renner.uno
+        state: absent

kubernetes/apps/paperless/paperless.yaml

@@ -144,6 +144,17 @@ metadata:
   annotations:
     cert-manager.io/cluster-issuer: letsencrypt-cluster
     nginx.ingress.kubernetes.io/proxy-body-size: "100m"
+    # Forward-auth into Authentik. Every request is bounced to the
+    # embedded outpost (in-cluster, no TLS) for an auth check;
+    # unauthenticated browsers are redirected to auth.renner.uno to
+    # sign in. Cookies are scoped to renner.uno via the matching
+    # forward_domain proxy provider in the Authentik blueprint, so
+    # all four paperless hostnames share the same session.
+    nginx.ingress.kubernetes.io/auth-url: "http://authentik-server.authentik.svc.cluster.local/outpost.goauthentik.io/auth/nginx"
+    nginx.ingress.kubernetes.io/auth-signin: "https://auth.renner.uno/outpost.goauthentik.io/start?rd=$scheme://$http_host$escaped_request_uri"
+    nginx.ingress.kubernetes.io/auth-response-headers: "Set-Cookie,X-authentik-username,X-authentik-groups,X-authentik-email,X-authentik-name,X-authentik-uid"
+    nginx.ingress.kubernetes.io/auth-snippet: |
+      proxy_set_header X-Forwarded-Host $http_host;
 spec:
   ingressClassName: nginx
   rules: