polish: extract inline CSS, add connection status, panel macro, favicon, ollama cache, toast system (#164)

Major:
- Extract all inline <style> blocks from 22 Jinja2 templates into
  static/css/mission-control.css — single cacheable stylesheet
- Add tox lint check that fails on inline <style> in templates

Minor:
1. Connection status indicator in topbar (green/amber/red dot) reflecting
   WebSocket + Ollama reachability, with auto-reconnect
2. Jinja2 {% macro panel(title) %} in macros.html — eliminates repeated
   .card.mc-panel markup; index.html converted as example
3. SVG favicon (purple T + orange dot)
4. 30-second TTL cache on _check_ollama() to avoid blocking the event loop
   on every health poll (asyncio.to_thread was already in place)
5. Toast notification system (McToast.show) for transient status messages —
   wired into connection status for Ollama/WebSocket state changes

Enforcement:
- CLAUDE.md updated with conventions 11-14 (no inline CSS, use panel macro,
  use toasts, never block the event loop)
- tox lint + pre-push environments now fail on inline <style> blocks

https://claude.ai/code/session_014FQ785MQdyJQ4BAXrRSo9w

Co-authored-by: Claude <noreply@anthropic.com>

src/dashboard/templates/index.html

@@ -1,4 +1,5 @@
 {% extends "base.html" %}
+{% from "macros.html" import panel %}
 
 {% block content %}
 
@@ -9,30 +10,16 @@
     <div class="col-12 col-md-3 d-flex flex-column gap-3 mc-sidebar">
 
       <!-- Agents (HTMX-polled from registry) -->
-      <div class="card mc-panel"
-           hx-get="/swarm/agents/sidebar"
-           hx-trigger="every 10s"
-           hx-target="this"
-           hx-swap="innerHTML">
-        <div class="card-header mc-panel-header">// AGENTS</div>
-        <div class="card-body p-3">
-          <div style="font-size:11px; color:var(--text-dim); letter-spacing:.08em;">LOADING...</div>
-        </div>
-      </div>
+      {% call panel("AGENTS", hx_get="/swarm/agents/sidebar", hx_trigger="every 10s") %}
+        <div style="font-size:11px; color:var(--text-dim); letter-spacing:.08em;">LOADING...</div>
+      {% endcall %}
 
       <!-- System Health (HTMX polled) -->
-      <div class="card mc-panel"
-           hx-get="/health/status"
-           hx-trigger="every 30s"
-           hx-target="this"
-           hx-swap="innerHTML">
-        <div class="card-header mc-panel-header">// SYSTEM HEALTH</div>
-        <div class="card-body p-3">
-          <div class="health-row">
-            <span class="health-label">LOADING...</span>
-          </div>
+      {% call panel("SYSTEM HEALTH", hx_get="/health/status", hx_trigger="every 30s") %}
+        <div class="health-row">
+          <span class="health-label">LOADING...</span>
         </div>
-      </div>
+      {% endcall %}
 
     </div>