lnbits, memos, mempool: use the caddy_site role

lnbits is the header_up shape; memos and mempool are the Tailscale MagicDNS
shape. 108 lines removed, 25 added.

mempool was the one playbook already reloading Caddy correctly
(systemd: state: reloaded rather than command: systemctl reload caddy), so
its end marker differed - the role's handler does the same thing.

Verified:
  - lnbits: full --check, site task ok, byte-identical to the live file
  - memos, mempool: --check --diff via --limit edge shows exactly one added
    line each, the standardised MagicDNS comment. Both playbooks fail earlier
    in check mode on their VM play ("Extract memos binary", the same
    download-does-not-happen-in-check-mode artifact as forgejo), but the edits
    are confined to the hosts: edge play - memos at line 169+, play 2 starts
    at 159; mempool at 617+, play 2 starts at 606.

The added comment means the next real run of memos/mempool rewrites one
comment line. Those two host files were already stale against their
playbooks before this change.

All 14 site files on all 3 hosts still byte-identical.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

ansible/services/mempool/deploy_mempool_playbook.yml

@@ -614,47 +614,16 @@
   vars:
     mempool_subdomain: "{{ subdomains.mempool }}"
     mempool_domain: "{{ mempool_subdomain }}.{{ root_domain }}"
-    caddy_sites_dir: "{{ caddy_sites_dir }}"
 
   tasks:
-    - name: Ensure Caddy sites-enabled directory exists
-      file:
-        path: "{{ caddy_sites_dir }}"
-        state: directory
-        owner: root
-        group: root
-        mode: '0755'
-
-    - name: Ensure Caddyfile includes import directive for sites-enabled
-      lineinfile:
-        path: /etc/caddy/Caddyfile
-        line: 'import sites-enabled/*'
-        insertafter: EOF
-        state: present
-        backup: yes
-        create: yes
-        mode: '0644'
-
-    - name: Create Caddy reverse proxy configuration for Mempool
-      copy:
-        dest: "{{ caddy_sites_dir }}/mempool.conf"
-        content: |
-          {{ mempool_domain }} {
-              reverse_proxy mempool-box:{{ mempool_frontend_port }} {
-                  # Use Tailscale MagicDNS to resolve the upstream hostname
-                  transport http {
-                      resolvers 100.100.100.100
-                  }
-              }
-          }
-        owner: root
-        group: root
-        mode: '0644'
-
-    - name: Reload Caddy to apply new config
-      systemd:
-        name: caddy
-        state: reloaded
+    - name: Publish Mempool through Caddy (via Tailscale)
+      ansible.builtin.include_role:
+        name: caddy_site
+      vars:
+        caddy_site_name: mempool
+        caddy_site_domain: "{{ mempool_domain }}"
+        caddy_site_upstream: "mempool-box:{{ mempool_frontend_port }}"
+        caddy_site_resolvers: "100.100.100.100"
 
     - name: Display Mempool URL
       when: uptime_kuma_enabled | default(false)