* `authentik_host_rewrite_domains`: extra hostnames that reach the
authentik container but make it generate URLs (OIDC issuer, reset
links) as if requested from the canonical `authentik_domains[0]`.
Each entry gets its own traefik router and a URL-based loadbalancer
service that disables passHostHeader and pins X-Forwarded-Host via
middleware, so server-to-server calls on internal FQDNs keep traffic
in the LAN while the iss claim stays aligned with the public host.
Uses a network alias on the canonical FQDN so traefik (sharing the
network) resolves the URL upstream to this very container.
* proxy-app blueprint:
- `mode` (default `forward_single`) lets callers pick between proxy,
forward_single and forward_domain providers in one template.
- `allowed_groups`: when set, emit one PolicyBinding per group on
the application; authentik OR-evaluates bindings, so users in any
listed group pass and others are denied.
Existing inventories with an empty list see no behavioural change.
- Refactor: collapse `*_domain` + `*_extra_domains` into a single
`*_domains` list across authentik, collabora, garage and nextcloud
roles. First entry is the canonical FQDN (used for OVERWRITEHOST,
BASE_URL, notify_push setup and garage root_domain).
- Authentik blueprint: guard the OAuth sources block so an empty
`authentik_login_sources` no longer renders an invalid YAML key.
- Nextcloud: introduce `nextcloud_collabora_public_domain` and set
Collabora's `public_wopi_url` separately from the server-to-server
`wopi_url` so browsers can reach Collabora via the public name while
Nextcloud still talks to it on the internal one.
- Nextcloud: URL-encode the postgres user/password in DATABASE_URL.
