docs(roles): add argument_specs and README for traefik, authentik, drawio, garage, nextcloud

Each of the five roles touched in this branch now ships:

* meta/argument_specs.yml: typed schema for every variable in
  defaults/main.yml plus the optional inputs surfaced via this
  branch (traefik_extra_hosts, authentik_host_rewrite_domains,
  authentik_proxy_apps.mode / .allowed_groups, drawio_extra_domains,
  drawio_authentik_forward_auth*, garage_webui_authentik_forward_auth*).
  All five specs load cleanly through ansible-core's
  ArgumentSpecValidator.

* README.md: replaces the ansible-galaxy boilerplate (where it was
  still in place) with a focused write-up — service vars, required
  secrets, ForwardAuth/idempotency notes, dependencies, and a working
  example playbook. authentik and garage READMEs are rewritten to cover
  the new knobs while preserving their existing content.

roles/drawio/README.md

@@ -1,38 +1,60 @@
-Role Name
-=========
+# Drawio
 
-A brief description of the role goes here.
+Ansible role to deploy [draw.io](https://www.drawio.com/) (the
+self-hosted `jgraph/drawio` container) via Docker Compose behind
+Traefik, with optional authentik ForwardAuth gating.
 
-Requirements
-------------
+## Requirements
 
-Any pre-requisites that may not be covered by Ansible itself or the role should be mentioned here. For instance, if the role uses the EC2 module, it may be a good idea to mention in this section that the boto package is required.
+- Docker and Docker Compose installed on the target host
+- Ansible collection: `community.docker`
+- Traefik with a shared `drawio_traefik_network` (default `proxy`)
+- For ForwardAuth: a reachable authentik embedded outpost endpoint
 
-Role Variables
---------------
+## Role variables
 
-A description of the settable variables for this role should go here, including any variables that are in defaults/main.yml, vars/main.yml, and any variables that can/should be set via parameters to the role. Any variables that are read from other roles and/or the global scope (ie. hostvars, group vars, etc.) should be mentioned here as well.
+Full spec with types and defaults: `meta/argument_specs.yml`. The most
+common overrides:
 
-Dependencies
-------------
+### Service
 
-A list of other roles hosted on Galaxy should go here, plus any details in regards to parameters that may need to be set for other roles, or variables that are used from other roles.
+- `drawio_domain`: canonical hostname used in the traefik Host rule
+  (default `drawio.local.test`).
+- `drawio_extra_domains`: additional hostnames the same container
+  should answer on (e.g. an internal `*.int.*` FQDN so a DMZ proxy
+  can reach drawio via a backend hostname).
+- `drawio_image`, `drawio_port`, `drawio_use_ssl`.
 
-Example Playbook
-----------------
+### Authentik ForwardAuth
 
-Including an example of how to use your role (for instance, with variables passed in as parameters) is always nice for users too:
+- `drawio_authentik_forward_auth`: set to `true` to gate the editor
+  behind authentik.
+- `drawio_authentik_forward_auth_url`: full URL of the embedded
+  outpost ForwardAuth endpoint, e.g.
+  `https://auth.example.com/outpost.goauthentik.io/auth/traefik`.
 
-    - hosts: servers
-      roles:
-         - { role: username.rolename, x: 42 }
+When enabled, traefik redirects unauthenticated requests to authentik
+for login and forwards the resulting `X-Authentik-*` identity headers
+downstream.
 
-License
--------
+## Dependencies
 
-BSD
+- Traefik network (`drawio_traefik_network`, default `proxy`)
+- Optional: authentik with a Proxy/ForwardAuth provider for drawio
+  (see the `authentik` role's `authentik_proxy_apps`).
 
-Author Information
-------------------
+## Example playbook
 
-An optional section for the role authors to include contact information, or a website (HTML is not allowed).
+```yaml
+- hosts: app_servers
+  roles:
+    - role: digitalboard.core.drawio
+      vars:
+        drawio_domain: "drawio.example.com"
+        drawio_authentik_forward_auth: true
+        drawio_authentik_forward_auth_url: "https://auth.example.com/outpost.goauthentik.io/auth/traefik"
+```
+
+## License
+
+MIT-0