feat: initialize market app with browsing, product, and scraping code

Split from coop monolith. Includes:
- Market/browse/product blueprints
- Product sync API
- Suma scraping pipeline
- Templates for market, browse, and product views
- Dockerfile and CI workflow for independent deployment

scrape/persist_api/save_nav.py

@@ -0,0 +1,19 @@
+# replace your existing upsert_product with this version
+
+import os
+import httpx
+
+from typing import Dict
+
+async def save_nav(
+    nav: Dict,
+):
+    sync_url = os.getenv("SAVE_NAV_URL", "http://localhost:8000/market/api/products/nav/")
+
+    async with httpx.AsyncClient(timeout=httpx.Timeout(20.0, connect=10.0)) as client:
+        resp = await client.post(sync_url, json=nav)
+    # Raise for non-2xx
+    resp.raise_for_status()
+    data = resp.json() if resp.content else {}
+    return data
+