Monorepo: consolidate 7 repos into one

Combines shared, blog, market, cart, events, federation, and account
into a single repository. Eliminates submodule sync, sibling model
copying at build time, and per-app CI orchestration.

Changes:
- Remove per-app .git, .gitmodules, .gitea, submodule shared/ dirs
- Remove stale sibling model copies from each app
- Update all 6 Dockerfiles for monorepo build context (root = .)
- Add build directives to docker-compose.yml
- Add single .gitea/workflows/ci.yml with change detection
- Add .dockerignore for monorepo build context
- Create __init__.py for federation and account (cross-app imports)

shared/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 %}