fix: add apt source debug tasks, fix arch mapping for Docker repo

ansible_facts['architecture'] returns x86_64 but Docker APT repo
expects amd64. Added docker_apt_arch mapping. Also added debug tasks
to show apt sources and apt-cache search results for docker-ce.

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Co-Authored-By: Devin <158243242+devin-ai-integration[bot]@users.noreply.github.com>

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

@@ -27,6 +27,30 @@
     cache_valid_time: 0
   when: ansible_facts['os_family'] == 'Debian'
 
+- name: Debug apt sources (Debian/Ubuntu)
+  ansible.builtin.shell: |
+    set -o pipefail
+    cat /etc/apt/sources.list.d/*.list /etc/apt/sources.list 2>/dev/null | grep -i docker || true
+  register: apt_docker_sources
+  changed_when: false
+  when: ansible_facts['os_family'] == 'Debian'
+
+- name: Show apt docker sources
+  ansible.builtin.debug:
+    var: apt_docker_sources.stdout_lines
+  when: ansible_facts['os_family'] == 'Debian'
+
+- name: Debug apt-cache search docker-ce
+  ansible.builtin.shell: apt-cache search docker-ce 2>/dev/null || true
+  register: apt_search_result
+  changed_when: false
+  when: ansible_facts['os_family'] == 'Debian'
+
+- name: Show apt-cache search result
+  ansible.builtin.debug:
+    var: apt_search_result.stdout_lines
+  when: ansible_facts['os_family'] == 'Debian'
+
 - name: Install rootless Docker dependencies (Debian/Ubuntu)
   ansible.builtin.apt:
     name: