feat: support multiple Gitea instances for actions runner

The gitea-actions role now uses a `gitea_runners` list instead of a
single `gitea_instance_url`. Each instance gets its own config, systemd
service, working directory, and cache. Migrates from the old single
`act_runner.service` to per-instance `act_runner-{name}.service`.

Adds git.skudak.com alongside git.debyl.io as runner targets.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

ansible/roles/gitea-actions/tasks/runner.yml

@@ -15,31 +15,36 @@
     mode: "0755"
   tags: gitea-actions
 
-- name: create act_runner working directory
+- name: create per-runner working directory
   become: true
   ansible.builtin.file:
-    path: "{{ act_runner_work_dir }}"
+    path: "{{ act_runner_work_dir }}/{{ item.name }}"
     state: directory
     owner: "{{ gitea_runner_user }}"
     group: "{{ gitea_runner_user }}"
     mode: "0755"
+  loop: "{{ gitea_runners }}"
   tags: gitea-actions
 
-- name: create act_runner cache directory
+- name: create per-runner cache directory
   become: true
   ansible.builtin.file:
-    path: "{{ act_runner_work_dir }}/cache"
+    path: "{{ act_runner_work_dir }}/{{ item.name }}/cache"
     state: directory
     owner: "{{ gitea_runner_user }}"
     group: "{{ gitea_runner_user }}"
     mode: "0755"
+  loop: "{{ gitea_runners }}"
   tags: gitea-actions
 
-- name: deploy act_runner configuration
+- name: deploy per-runner configuration
   become: true
   ansible.builtin.template:
     src: config.yaml.j2
-    dest: "{{ act_runner_config_dir }}/config.yaml"
+    dest: "{{ act_runner_config_dir }}/config-{{ item.name }}.yaml"
     mode: "0644"
-  notify: restart act_runner
+  vars:
+    runner_name: "{{ item.name }}"
+  loop: "{{ gitea_runners }}"
+  notify: restart act_runner services
   tags: gitea-actions