feat: UI redesign (CSS system, DNS widget, Traefik dashboard widget)

- Replace base.html style block with full CSS design system using custom properties (dark theme, cards, tables, badges, dots, widgets)
- Add DNS blueprint (fablednetmon/dns/) with /dns/ and /dns/rows routes + templates
- Add Traefik /widget route and widget.html fragment for dashboard
- Update dashboard: DNS + Traefik widgets, traefik_enabled config detection
- Update all templates to use new CSS classes (page-title, section-title, card-flush, table, badge-*, dot-*, btn-*)
- Register dns_bp in app.py

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

fablednetmon/templates/ansible/run_detail.html

@@ -3,7 +3,7 @@
 {% block content %}
 <div style="display:flex;align-items:center;gap:1rem;margin-bottom:1.5rem;">
     <a href="/ansible/" style="color:#6060c0;font-size:0.9rem;">← Runs</a>
-    <h1 style="color:#c0c0ff;">Run Detail</h1>
+    <h1 class="page-title" style="margin-bottom:0;">Run Detail</h1>
 </div>
 
 {% set status_color = {"running": "#a0a000", "success": "#40a040", "failed": "#a04040", "interrupted": "#806040"}.get(run.status.value, "#808080") %}