feat(docker): Swarm task awareness — replaced tasks, service crash loops, last task error

Milestone 465 "Swarm task awareness". Fixes three defects from the live MCP
review #4973:
- #5008 "Swarm task history read as live state"
- #5009 "Crash-loop detection is blind to Swarm services"
- #5011 "Swarm task errors are not captured"

Agent and ingest (agent 1.8.0):
- A manager's agent now reports each service's newest tasks: slot, node,
  desired and current state, Swarm's Err/Message, exit code and time.
- They are stored in docker_swarm_services.tasks_json (migration
  docker_010_swarm_tasks).

Swarm view (pure):
- A task container is "replaced" when Swarm set its task's desired state off
  `running`. Without the task on record, a newer or running task in the same
  slot decides.
- Replaced containers are no longer replicas or crashes.
- Each service gets, from the task records:
  - failures_1h and failures_24h (failed or rejected tasks);
  - crash_looping (Settings → Thresholds count);
  - last_error, in Swarm's own words.

MCP:
- New findings: swarm_service_crash_looping (critical) and swarm_task_failed
  (warning, on a healthy service with a failure in 24h).
- Down and degraded findings name the last task error.
- list_swarm_services carries the failure fields.
- Container rows mark swarm_replaced and give a replaced task no problems.

Web:
- The containers page swarm cards and the Swarm topology page show crash
  loops, recent failures and the last task error.
- The dashboard widget flags a crash loop, and its "failed (24h)" count no
  longer counts a rolling update's killed task.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

plugins/docker/templates/docker/swarm.html

@@ -22,7 +22,7 @@
     <table class="table">
       <thead>
         <tr>
-          <th>Service</th><th>Mode</th><th>Replicas</th><th>Image</th><th>Placement</th>
+          <th>Service</th><th>Mode</th><th>Replicas</th><th>Image</th><th>Placement</th><th>Task failures</th>
         </tr>
       </thead>
       <tbody>
@@ -39,9 +39,14 @@
           <td style="font-size:0.78rem;color:var(--text-muted);">
             {% for p in s.placement %}{{ p.node }} ({{ p.running }}){% if not loop.last %}, {% endif %}{% else %}—{% endfor %}
           </td>
+          <td style="max-width:360px;">
+            {% include "docker/_swarm_failures.html" %}
+            {%- if not s.tasks_known %}<span style="font-size:0.78rem;color:var(--text-dim);" title="The reporting manager's agent predates task reporting (1.8.0); update it to see task failures.">—</span>
+            {%- elif not (s.crash_looping or s.failures_24h or (s.last_error and s.state != 'healthy')) %}<span style="font-size:0.78rem;color:var(--text-dim);">none in 24h</span>{% endif %}
+          </td>
         </tr>
         {% else %}
-        <tr><td colspan="5" style="color:var(--text-muted);font-size:0.85rem;text-align:center;padding:1.5rem;">No services in this swarm.</td></tr>
+        <tr><td colspan="6" style="color:var(--text-muted);font-size:0.85rem;text-align:center;padding:1.5rem;">No services in this swarm.</td></tr>
         {% endfor %}
       </tbody>
     </table>