feat: extract shared infrastructure from shared_lib

Phase 1-3 of decoupling plan:
- Shared DB, models, infrastructure, browser, config, utils
- Event infrastructure (domain_events outbox, bus, processor)
- Structured logging
- Generic container concept (container_type/container_id)
- Alembic migrations for all schema changes

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

browser/templates/sentinel/desktop_content.html

@@ -0,0 +1,9 @@
+<div class="js-loading text-center text-xs text-stone-400">
+    loading… {{ page }} / {{ total_pages }}
+  </div>
+
+   <div class="js-neterr hidden inset-0 grid place-items-center p-4">
+    <div class="w-full max-w-[360px]">
+      {% include "sentinel/wireless_error.svg" %}
+    </div>
+  </div>

browser/templates/sentinel/mobile_content.html

@@ -0,0 +1,11 @@
+ <!-- tiny loading text (default) -->
+  <div class="js-loading text-center text-xs text-stone-400">
+    loading… {{ page }} / {{ total_pages }}
+  </div>
+
+  <!-- BIG error panel (hidden by default) -->
+  <div class="js-neterr hidden flex h-full items-center justify-center">
+    <!-- Funky SVG: unplugged cable + pulse -->
+
+    {% include "sentinel/wireless_error.svg" %}
+  </div>

browser/templates/sentinel/wireless_error.svg

@@ -0,0 +1,20 @@
+<svg fill="#f5a40cff" version="1.1" id="Capa_1" xmlns="http://www.w3.org/2000/svg"
+	 width="800px" height="800px" viewBox="0 0 862.899 862.9"
+	 xml:space="preserve"
+   class="block w-full h-auto max-h-full"  preserveAspectRatio="xMidYMid meet"
+>
+<g>
+	<g>
+		<circle cx="385.6" cy="656.1" r="79.8"/>
+		<path d="M561.7,401c-15.801-10.3-32.601-19.2-50.2-26.6c-39.9-16.9-82.3-25.5-126-25.5c-44.601,0-87.9,8.9-128.6,26.6
+			c-39.3,17-74.3,41.3-104.1,72.2L253.5,545c34.899-36.1,81.8-56,132-56c49,0,95.1,19.1,129.8,53.8l25.4-25.399L493,469.7L561.7,401
+			z"/>
+		<path d="M385.6,267.1c107.601,0,208.9,41.7,285.3,117.4l98.5-99.5c-50-49.5-108.1-88.4-172.699-115.6
+			c-66.9-28.1-138-42.4-211.101-42.4c-73.6,0-145,14.4-212.3,42.9c-65,27.5-123.3,66.8-173.3,116.9l99,99
+			C175.5,309.299,277.3,267.1,385.6,267.1z"/>
+		<polygon points="616.8,402.5 549.7,469.599 639.2,559.099 549.7,648.599 616.8,715.7 706.3,626.2 795.8,715.7 862.899,648.599
+			773.399,559.099 862.899,469.599 795.8,402.5 706.3,492 		"/>
+	</g>
+</g>
+</svg>
+