feat: initial shared library extraction

Contains shared infrastructure for all coop services:
- shared/ (factory, urls, user_loader, context, internal_api, jinja_setup)
- models/ (User, Order, Calendar, Ticket, Product, Ghost CMS)
- db/ (SQLAlchemy async session, base)
- suma_browser/app/ (csrf, middleware, errors, authz, redis_cacher, payments, filters, utils)
- suma_browser/templates/ (shared base layouts, macros, error pages)
- static/ (CSS, JS, fonts, images)
- alembic/ (database migrations)
- config/ (app-config.yaml)
- editor/ (Lexical editor Node.js build)
- requirements.txt

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

static/labels/_blank.svg

@@ -0,0 +1,17 @@
+<svg xmlns="http://www.w3.org/2000/svg"
+     viewBox="0 0 200 200" width="200" height="200" role="img" aria-labelledby="title">
+  <title id="title">Offer ribbon (top-right)</title>
+
+  <!-- Ribbon group: move origin to top-right, then rotate 45° -->
+  <g transform="translate(200 0) rotate(45)">
+    <!-- The stripe -->
+    <rect x="-160" y="50" width="320" height="25" rx="4" fill="#22c55e"/>
+    <!-- Label on the stripe (centered) -->
+    <text x="0" y="65"
+          font-family="system-ui, -apple-system, Segoe UI, Roboto, Helvetica, Arial, sans-serif"
+          font-size="18" font-weight="800" fill="#ffffff"
+          text-anchor="middle" dominant-baseline="middle" letter-spacing=".15em">
+      NEW
+    </text>
+  </g>
+</svg>

static/labels/new.svg

@@ -0,0 +1,17 @@
+<svg xmlns="http://www.w3.org/2000/svg"
+     viewBox="0 0 200 200" width="200" height="200" role="img" aria-labelledby="title">
+  <title id="title">Offer ribbon (top-right)</title>
+
+  <!-- Ribbon group: move origin to top-right, then rotate 45° -->
+  <g transform=" rotate(-45 0 0)">
+    <!-- The stripe -->
+    <rect x="-160" y="25" width="320" height="25" rx="4" fill="#22c55e"/>
+    <!-- Label on the stripe (centered) -->
+    <text x="0" y="40"
+          font-family="system-ui, -apple-system, Segoe UI, Roboto, Helvetica, Arial, sans-serif"
+          font-size="18" font-weight="800" fill="#ffffff"
+          text-anchor="middle" dominant-baseline="middle" letter-spacing=".15em">
+      NEW
+    </text>
+  </g>
+</svg>

static/labels/offer.svg

@@ -0,0 +1,19 @@
+<svg xmlns="http://www.w3.org/2000/svg"
+     viewBox="0 0 200 200" width="200" height="200" role="img" aria-labelledby="title">
+  <title id="title">Offer ribbon</title>
+
+  <!-- Transparent background (nothing drawn) -->
+
+  <!-- Ribbon group rotated -45° around the top-left corner (0,0) -->
+  <g transform="rotate(-45 0 0)">
+    <!-- The stripe itself -->
+    <rect x="-80" y="50" width="260" height="25" rx="4" fill="#ef4444"/>
+    <!-- Centered label on the stripe -->
+    <text x="0" y="65"
+          font-family="system-ui, -apple-system, Segoe UI, Roboto, Helvetica, Arial, sans-serif"
+          font-size="18" font-weight="800" fill="#ffffff"
+          text-anchor="middle" dominant-baseline="middle" letter-spacing=".15em">
+      OFFER
+    </text>
+  </g>
+</svg>