monitor : temp GPU, conso watts, espace disque, heartbeat dispatcher

- nvidia-smi : +temperature.gpu + power.draw
- UI : tags °C / W / espace disque libre
- Dispatcher heartbeat toutes les 4s → point vert/rouge en haut du monitor
- Fix Docker SSH : copie + chmod 600 au démarrage (Bad owner)

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

app/templates/_monitor.html

@@ -1,3 +1,17 @@
+<div class="monitor-header">
+  <div class="dispatcher-status {% if dispatcher.alive %}alive{% else %}dead{% endif %}">
+    <span class="dot"></span>
+    dispatcher
+    {% if dispatcher.alive %}
+      <span class="muted">· il y a {{ dispatcher.age_s }}s</span>
+    {% elif dispatcher.age_s is not none %}
+      <span class="muted">· last seen {{ dispatcher.age_s }}s ago</span>
+    {% else %}
+      <span class="muted">· non démarré</span>
+    {% endif %}
+  </div>
+</div>
+
 <div class="worker-grid">
   {% for w in workers %}
     <div class="worker {% if not w.online %}offline{% endif %}">
@@ -17,7 +31,12 @@
           <progress value="{{ w.gpu_util_pct or 0 }}" max="100"></progress>
           <small>{{ w.gpu_util_pct }}%</small>
         </div>
-        <div class="bar"><span>Disk /</span><small>{{ w.disk_used_pct }}</small></div>
+        <div class="worker-meta">
+          {% if w.gpu_temp_c is not none %}<span class="tag {% if w.gpu_temp_c > 80 %}warn{% endif %}">{{ w.gpu_temp_c }}°C</span>{% endif %}
+          {% if w.gpu_power_w is not none %}<span class="tag">{{ w.gpu_power_w }}W</span>{% endif %}
+          <span class="tag muted">/ {{ w.disk_avail }} dispo</span>
+          <span class="tag muted">{{ w.disk_used_pct }} utilisé</span>
+        </div>
       {% else %}
         <div class="err">{{ w.error or "unreachable" }}</div>
       {% endif %}