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>

suma_browser/templates/macros/glyphs.html

@@ -0,0 +1,17 @@
+{% macro opener(group=False) %}
+    <svg
+        class="h-4 w-4 transition-transform group-open{{ '/' + group if group else ''}}:rotate-180"
+        xmlns="http://www.w3.org/2000/svg"
+        viewBox="0 0 24 24"
+        fill="none"
+        stroke="currentColor"
+      >
+        <path
+          stroke-linecap="round"
+          stroke-linejoin="round"
+          stroke-width="2"
+          d="M6 9l6 6 6-6"
+        />
+      </svg>
+
+{% endmacro %}