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/links.html

@@ -0,0 +1,59 @@
+
+
+{% macro link(url, select, select_colours='', highlight=True, _class='', aclass='') %}
+    {% set href=url|host%}
+    <div class="relative nav-group {{_class}}">
+      <a
+        href="{{ href }}"
+        hx-get="{{ href }}"
+        hx-target="#main-panel"
+        hx-select="{{select}}"
+        hx-swap="outerHTML"
+        hx-push-url="true"
+        aria-selected="{{ 'true' if (request.path|host).startswith(href) else 'false' }}"
+        {% if aclass %}
+          class="{{aclass}}"
+        {% elif select_colours %}
+          class="whitespace-normal flex gap-2 px-3 py-2 rounded
+            text-center break-words leading-snug
+            bg-stone-200 text-black
+            {{select_colours if highlight else ''}}
+          "
+        {% else %}
+          class="w-full whitespace-normal flex items-center gap-2 font-bold text-2xl px-3 py-2"
+        {% endif %}
+      >
+        {{ caller() }}
+      </a>
+    </div>
+{% endmacro %}
+
+
+{% macro menu_row(id=False, oob=False) %}
+  <div
+    {% if id %}
+      id="{{id}}"
+    {% endif %}
+    {% if oob %}
+      hx-swap-oob="outerHTML"
+    {% endif %}
+    class="flex flex-col items-center md:flex-row justify-center md:justify-between w-full p-1 bg-{{menu_colour}}-{{(500-(level()*100))|string}}"
+  >
+    {{ caller() }}
+  </div>
+  {{level_up()}}
+{% endmacro %}
+
+{% macro desktop_nav() %}
+  <nav class="hidden md:flex gap-4 text-sm ml-2 justify-end items-center flex-0">
+    {{ caller() }}
+  </nav>
+{% endmacro %}
+
+{% macro admin() %}
+  <i class="fa fa-cog" aria-hidden="true"></i>
+  <div>
+    settings
+  </div>
+
+{% endmacro %}