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/order/a-z.svg

@@ -0,0 +1,10 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<svg width="24" height="24" viewBox="0 0 24 24"
+     xmlns="http://www.w3.org/2000/svg" role="img" aria-label="Sort A to Z">
+  <!-- Orange rounded square -->
+  <rect x="1" y="1" width="22" height="22" rx="5" fill="#F97316"/>
+  <!-- A–Z label -->
+  <text x="12" y="12" text-anchor="middle" dominant-baseline="middle"
+        font-family="system-ui, -apple-system, BlinkMacSystemFont, Segoe UI, Roboto, Arial, sans-serif"
+        font-size="9" font-weight="700" fill="#FFFFFF">A–Z</text>
+</svg>

static/order/h-l.svg

@@ -0,0 +1,10 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<svg width="24" height="24" viewBox="0 0 24 24"
+     xmlns="http://www.w3.org/2000/svg" role="img" aria-label="Sort £ hi to Lo">
+  <!-- Orange rounded square -->
+  <rect x="1" y="1" width="22" height="22" rx="5" fill="#F97316"/>
+  <!-- A–Z label -->
+  <text x="12" y="12" text-anchor="middle" dominant-baseline="middle"
+        font-family="system-ui, -apple-system, BlinkMacSystemFont, Segoe UI, Roboto, Arial, sans-serif"
+        font-size="9" font-weight="700" fill="#FFFFFF">£ ↓</text>
+</svg>

static/order/l-h.svg

@@ -0,0 +1,10 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<svg width="24" height="24" viewBox="0 0 24 24"
+     xmlns="http://www.w3.org/2000/svg" role="img" aria-label="Sort £ lo to hi">
+  <!-- Orange rounded square -->
+  <rect x="1" y="1" width="22" height="22" rx="5" fill="#F97316"/>
+  <!-- A–Z label -->
+  <text x="12" y="12" text-anchor="middle" dominant-baseline="middle"
+        font-family="system-ui, -apple-system, BlinkMacSystemFont, Segoe UI, Roboto, Arial, sans-serif"
+        font-size="9" font-weight="700" fill="#FFFFFF">£ ↑</text>
+</svg>

static/order/z-a.svg

@@ -0,0 +1,10 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<svg width="24" height="24" viewBox="0 0 24 24"
+     xmlns="http://www.w3.org/2000/svg" role="img" aria-label="Sort Z to A">
+  <!-- Orange rounded square -->
+  <rect x="1" y="1" width="22" height="22" rx="5" fill="#F97316"/>
+  <!-- A–Z label -->
+  <text x="12" y="12" text-anchor="middle" dominant-baseline="middle"
+        font-family="system-ui, -apple-system, BlinkMacSystemFont, Segoe UI, Roboto, Arial, sans-serif"
+        font-size="9" font-weight="700" fill="#FFFFFF">Z-A</text>
+</svg>