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/infrastructure/urls.py

@@ -0,0 +1,97 @@
+from __future__ import annotations
+
+import os
+from urllib.parse import quote
+
+from shared.config import config
+
+
+def _get_app_url(app_name: str) -> str:
+    env_key = f"APP_URL_{app_name.upper()}"
+    env_val = os.getenv(env_key)
+    if env_val:
+        return env_val.rstrip("/")
+    return config()["app_urls"][app_name].rstrip("/")
+
+
+def app_url(app_name: str, path: str = "/") -> str:
+    base = _get_app_url(app_name)
+    if not path.startswith("/"):
+        path = "/" + path
+    return base + path
+
+
+def blog_url(path: str = "/") -> str:
+    return app_url("blog", path)
+
+
+def market_url(path: str = "/") -> str:
+    return app_url("market", path)
+
+
+def cart_url(path: str = "/") -> str:
+    return app_url("cart", path)
+
+
+def events_url(path: str = "/") -> str:
+    return app_url("events", path)
+
+
+def federation_url(path: str = "/") -> str:
+    return app_url("federation", path)
+
+
+def account_url(path: str = "/") -> str:
+    return app_url("account", path)
+
+
+def artdag_url(path: str = "/") -> str:
+    return app_url("artdag", path)
+
+
+def page_cart_url(page_slug: str, path: str = "/") -> str:
+    if not path.startswith("/"):
+        path = "/" + path
+    return cart_url(f"/{page_slug}{path}")
+
+
+def market_product_url(product_slug: str, suffix: str = "", market_place=None) -> str:
+    """Build a market product URL with the correct page/market prefix.
+
+    Resolves the prefix from:
+      - market app context: g.post_slug + g.market_slug
+      - cart app context:   g.page_slug + market_place.slug
+    """
+    from quart import g
+
+    page_slug = getattr(g, "post_slug", None) or getattr(g, "page_slug", None)
+    ms = getattr(g, "market_slug", None) or (
+        getattr(market_place, "slug", None) if market_place else None
+    )
+    prefix = f"/{page_slug}/{ms}" if page_slug and ms else ""
+    tail = f"/{suffix}" if suffix else "/"
+    return market_url(f"{prefix}/product/{product_slug}{tail}")
+
+
+def login_url(next_url: str = "") -> str:
+    from quart import current_app
+
+    # Account handles login directly (magic link flow — it's the OAuth server)
+    if current_app.name == "account":
+        base = "/auth/login/"
+        params: list[str] = []
+        if next_url:
+            params.append(f"next={quote(next_url, safe='')}")
+        from quart import session as qsession
+        cart_sid = qsession.get("cart_sid")
+        if cart_sid:
+            params.append(f"cart_sid={quote(cart_sid, safe='')}")
+        if params:
+            return f"{base}?{'&'.join(params)}"
+        return base
+
+    # Client apps: local /auth/login triggers OAuth redirect to account
+    base = "/auth/login/"
+    if next_url:
+        return f"{base}?next={quote(next_url, safe='')}"
+    return base