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)

federation/templates/auth/check_email.html

@@ -0,0 +1,19 @@
+{% extends "_types/root/_index.html" %}
+{% block meta %}{% endblock %}
+{% block title %}Check your email — Rose Ash{% endblock %}
+{% block content %}
+<div class="py-8 max-w-md mx-auto text-center">
+  <h1 class="text-2xl font-bold mb-4">Check your email</h1>
+  <p class="text-stone-600 mb-2">
+    We sent a sign-in link to <strong>{{ email }}</strong>.
+  </p>
+  <p class="text-stone-500 text-sm">
+    Click the link in the email to sign in. The link expires in 15 minutes.
+  </p>
+  {% if email_error %}
+    <div class="bg-yellow-50 border border-yellow-200 text-yellow-700 p-3 rounded mt-4">
+      {{ email_error }}
+    </div>
+  {% endif %}
+</div>
+{% endblock %}