feat: restructure market app with per-market URL scoping

- URL structure changes from /<route> to /<market_slug>/<route>
- Root / shows markets listing page
- app.py: url_value_preprocessor, url_defaults, hydrate_market (events app pattern)
- Browse queries (db_nav, db_products_nocounts, db_products_counts) accept market_id
- _productInfo reads g.market.id to scope all queries
- save_nav accepts market_id, sets on new NavTop rows
- API save_nav passes g.market.id
- Scraper default URLs point to /suma-market/ on port 8001

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

bp/api/routes.py

@@ -338,7 +338,9 @@ async def rediects():
 @clear_cache(tag='browse')
 async def save_nav():
     data: Dict[str, Any] = await request.get_json(force=True, silent=False)
-    await _save_nav(g.s, data)
+    market = getattr(g, "market", None)
+    market_id = market.id if market else None
+    await _save_nav(g.s, data, market_id=market_id)
     return {"ok": True}