feat: extract shared infrastructure from shared_lib

Phase 1-3 of decoupling plan:
- Shared DB, models, infrastructure, browser, config, utils
- Event infrastructure (domain_events outbox, bus, processor)
- Structured logging
- Generic container concept (container_type/container_id)
- Alembic migrations for all schema changes

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

infrastructure/urls.py

@@ -0,0 +1,49 @@
+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 coop_url(path: str = "/") -> str:
+    return app_url("coop", 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 page_cart_url(page_slug: str, path: str = "/") -> str:
+    if not path.startswith("/"):
+        path = "/" + path
+    return cart_url(f"/{page_slug}{path}")
+
+
+def login_url(next_url: str = "") -> str:
+    if next_url:
+        return coop_url(f"/auth/login/?next={quote(next_url, safe='')}")
+    return coop_url("/auth/login/")