fix(acp-gemini): create runtime dirs so service WorkingDirectory exists

acp-gemini.service sets WorkingDirectory={{ acp_gemini_workdir }} (~/.gemini)
but the role never created it, so systemd failed at step CHDIR (status
200/CHDIR), the adapter never bound 127.0.0.1:8791, and the CORS preflight
validation failed after 30 retries. Mirror the opencode role: pre-create the
home, .gemini workdir, XDG config and state dirs owned by the service user.
Linux/Debian only (guarded != Darwin); macOS uses the launchd path.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

roles/vhosts/acp_server_gemini/tasks/config.yml

@@ -69,6 +69,21 @@
   changed_when: true
   become: true
 
+- name: Ensure Gemini ACP runtime directories exist
+  ansible.builtin.file:
+    path: "{{ item }}"
+    state: directory
+    owner: "{{ acp_gemini_service_user }}"
+    group: "{{ acp_gemini_service_group }}"
+    mode: "0755"
+  loop:
+    - "{{ acp_gemini_home }}"
+    - "{{ acp_gemini_workdir }}"
+    - "{{ acp_gemini_xdg_config_home }}"
+    - "{{ acp_gemini_xdg_state_home }}"
+  become: true
+  when: ansible_os_family != 'Darwin'
+
 - name: Deploy Gemini ACP systemd service
   ansible.builtin.command:
     cmd: lsattr "/etc/systemd/system/{{ acp_gemini_service_name }}.service"