feat: add weekly Gitea disk cleanup Ansible playbook

Gitea LXC 225 hit 100% disk from accumulated Docker buildx volumes,
repo-archive cache, and journal logs. Adds automated weekly cleanup
managed by systemd timer on the Ansible controller (Wed 04:00 UTC).

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

ansible/playbooks/gitea-cleanup.yml

@@ -0,0 +1,80 @@
+---
+# gitea-cleanup.yml — Weekly cleanup of Gitea server disk space
+#
+# Removes stale Docker buildx volumes, unused images, Gitea repo-archive
+# cache, and vacuums journal logs to prevent disk exhaustion on LXC 225.
+#
+# Schedule: Weekly via systemd timer on LXC 304 (ansible-controller)
+#
+# Usage:
+#   ansible-playbook /opt/ansible/playbooks/gitea-cleanup.yml          # full run
+#   ansible-playbook /opt/ansible/playbooks/gitea-cleanup.yml --check  # dry run
+
+- name: Gitea server disk cleanup
+  hosts: gitea
+  gather_facts: false
+
+  tasks:
+    - name: Check current disk usage
+      ansible.builtin.shell: df --output=pcent / | tail -1
+      register: disk_before
+      changed_when: false
+
+    - name: Display current disk usage
+      ansible.builtin.debug:
+        msg: "Disk usage before cleanup: {{ disk_before.stdout | trim }}"
+
+    - name: Clear Gitea repo-archive cache
+      ansible.builtin.find:
+        paths: /var/lib/gitea/data/repo-archive
+        file_type: any
+      register: repo_archive_files
+
+    - name: Remove repo-archive files
+      ansible.builtin.file:
+        path: "{{ item.path }}"
+        state: absent
+      loop: "{{ repo_archive_files.files }}"
+      loop_control:
+        label: "{{ item.path | basename }}"
+      when: repo_archive_files.files | length > 0
+
+    - name: Remove orphaned Docker buildx volumes
+      ansible.builtin.shell: |
+        volumes=$(docker volume ls -q --filter name=buildx_buildkit)
+        if [ -n "$volumes" ]; then
+          echo "$volumes" | xargs docker volume rm 2>&1
+        else
+          echo "No buildx volumes to remove"
+        fi
+      register: buildx_cleanup
+      changed_when: "'No buildx volumes' not in buildx_cleanup.stdout"
+
+    - name: Prune unused Docker images
+      ansible.builtin.command: docker image prune -af
+      register: image_prune
+      changed_when: "'Total reclaimed space: 0B' not in image_prune.stdout"
+
+    - name: Prune unused Docker volumes
+      ansible.builtin.command: docker volume prune -f
+      register: volume_prune
+      changed_when: "'Total reclaimed space: 0B' not in volume_prune.stdout"
+
+    - name: Vacuum journal logs to 500M
+      ansible.builtin.command: journalctl --vacuum-size=500M
+      register: journal_vacuum
+      changed_when: "'freed 0B' not in journal_vacuum.stderr"
+
+    - name: Check disk usage after cleanup
+      ansible.builtin.shell: df --output=pcent / | tail -1
+      register: disk_after
+      changed_when: false
+
+    - name: Display cleanup summary
+      ansible.builtin.debug:
+        msg: >-
+          Cleanup complete.
+          Disk: {{ disk_before.stdout | default('N/A') | trim }} → {{ disk_after.stdout | default('N/A') | trim }}.
+          Buildx: {{ (buildx_cleanup.stdout_lines | default(['N/A'])) | last }}.
+          Images: {{ (image_prune.stdout_lines | default(['N/A'])) | last }}.
+          Journal: {{ (journal_vacuum.stderr_lines | default(['N/A'])) | last }}.