uptime-kuma: add uptime_kuma_enabled flag and make monitoring blocks inert

Removing the credentials would otherwise break these playbooks mid-deploy: they
template uptime_kuma_password with no assert to stop them first. 100 tasks are
now guarded by uptime_kuma_enabled (false), so deployments run normally and the
monitoring sections skip. A further 28 tasks were already self-guarding on
monitor_setup/push_url being defined; verified that a skipped task's registered
variable makes those skip cleanly rather than error.

The blocks are kept on purpose — the health-check logic is the durable part and
should be rewired to whatever replaces Uptime Kuma.

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

ansible/services/bitcoin-knots/deploy_bitcoin_knots_playbook.yml

@@ -439,7 +439,18 @@
       debug:
         msg: "Bitcoin Knots RPC is {{ 'available' if rpc_check.status == 200 else 'not yet available' }}"
 
+    # ═════════════════════════════════════════════════════════════════════════
+    # DEPRECATED — Uptime Kuma was decommissioned on 2026-09-11.
+    #
+    # Every task below is inert: uptime_kuma_enabled is false in
+    # group_vars/all/main.yml, so they all skip and the deployment above still
+    # runs normally. Kept because the health-check logic is the durable part —
+    # when a replacement exists, rewire the push transport and flip the flag.
+    #
+    # What was being monitored: archive/uptime_kuma/MONITORS.md
+    # ═════════════════════════════════════════════════════════════════════════
     - name: Create Bitcoin Knots health check and push script
+      when: uptime_kuma_enabled | default(false)
       copy:
         dest: /usr/local/bin/bitcoin-knots-healthcheck-push.sh
         content: |
@@ -534,6 +545,7 @@
         mode: '0644'
 
     - name: Create systemd service for Bitcoin Knots health check
+      when: uptime_kuma_enabled | default(false)
       copy:
         dest: /etc/systemd/system/bitcoin-knots-healthcheck.service
         content: |
@@ -566,6 +578,7 @@
         state: started
 
     - name: Create Uptime Kuma push monitor setup script for Bitcoin Knots
+      when: uptime_kuma_enabled | default(false)
       delegate_to: localhost
       become: no
       copy:
@@ -655,6 +668,7 @@
         mode: '0755'
 
     - name: Create temporary config for monitor setup
+      when: uptime_kuma_enabled | default(false)
       delegate_to: localhost
       become: no
       copy:
@@ -667,6 +681,7 @@
         mode: '0644'
 
     - name: Run Uptime Kuma push monitor setup
+      when: uptime_kuma_enabled | default(false)
       command: python3 /tmp/setup_bitcoin_knots_monitor.py
       delegate_to: localhost
       become: no
@@ -707,6 +722,7 @@
       when: uptime_kuma_push_url | default('') != ''
 
     - name: Clean up temporary files
+      when: uptime_kuma_enabled | default(false)
       delegate_to: localhost
       become: no
       file:
@@ -718,6 +734,7 @@
 
   handlers:
     - name: Restart bitcoind
+      when: uptime_kuma_enabled | default(false)
       systemd:
         name: bitcoind
         state: restarted
@@ -794,6 +811,7 @@
       ignore_errors: yes
 
     - name: Display public endpoint
+      when: uptime_kuma_enabled | default(false)
       debug:
         msg: "Bitcoin P2P public endpoint: {{ ansible_host }}:{{ bitcoin_p2p_port }}"
 
@@ -801,6 +819,7 @@
     # Uptime Kuma TCP Monitor for Public P2P
     # ===========================================
     - name: Create Uptime Kuma TCP monitor setup script for Bitcoin P2P
+      when: uptime_kuma_enabled | default(false)
       delegate_to: localhost
       become: no
       copy:
@@ -873,6 +892,7 @@
         mode: '0755'
 
     - name: Create temporary config for TCP monitor setup
+      when: uptime_kuma_enabled | default(false)
       delegate_to: localhost
       become: no
       copy:
@@ -887,6 +907,7 @@
         mode: '0644'
 
     - name: Run Uptime Kuma TCP monitor setup
+      when: uptime_kuma_enabled | default(false)
       command: python3 /tmp/setup_bitcoin_p2p_tcp_monitor.py
       delegate_to: localhost
       become: no
@@ -900,6 +921,7 @@
       when: tcp_monitor_setup.stdout is defined
 
     - name: Clean up TCP monitor temporary files
+      when: uptime_kuma_enabled | default(false)
       delegate_to: localhost
       become: no
       file: