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>

static/nav-labels/new.svg

@@ -0,0 +1,14 @@
+<svg xmlns="http://www.w3.org/2000/svg"
+     viewBox="0 0 100 100" width="100" height="100" role="img" aria-labelledby="title">
+  <title id="title">New</title>
+
+    <!-- The stripe -->
+    <rect x="0" y="30" width="100" height="40" rx="4" fill="#22c55e"/>
+    <!-- Label on the stripe (centered) -->
+    <text x="52" y="52"
+          font-family="system-ui, -apple-system, Segoe UI, Roboto, Helvetica, Arial, sans-serif"
+          font-size="25" font-weight="800" fill="#ffffff"
+          text-anchor="middle" dominant-baseline="middle" letter-spacing=".15em">
+      NEW
+    </text>
+</svg>

static/nav-labels/offer.svg

@@ -0,0 +1,16 @@
+
+
+<svg xmlns="http://www.w3.org/2000/svg"
+     viewBox="0 0 100 100" width="100" height="100" role="img" aria-labelledby="title">
+  <title id="title">Offer</title>
+
+    <!-- The stripe -->
+    <rect x="0" y="30" width="100" height="40" rx="4" fill="#22c55e"/>
+    <!-- Label on the stripe (centered) -->
+    <text x="52" y="52"
+          font-family="system-ui, -apple-system, Segoe UI, Roboto, Helvetica, Arial, sans-serif"
+          font-size="25" font-weight="800" fill="#ffffff"
+          text-anchor="middle" dominant-baseline="middle" letter-spacing=".15em">
+      OFFER
+    </text>
+</svg>