feat: decouple market from shared_lib, add app-owned models

Phase 1-3 of decoupling:
- path_setup.py adds project root to sys.path
- Market-owned models in market/models/ (market, market_place)
- All imports updated: shared.infrastructure, shared.db, shared.browser, etc.
- MarketPlace uses container_type/container_id instead of post_id FK

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

app.py

@@ -7,11 +7,10 @@ from quart import g, abort, render_template, make_response
 from jinja2 import FileSystemLoader, ChoiceLoader
 from sqlalchemy import select
 
-from shared.factory import create_base_app
-from shared.cart_loader import load_cart
-from config import config
+from shared.infrastructure.factory import create_base_app
+from shared.config import config
 
-from suma_browser.app.bp import register_market_bp
+from bp import register_market_bp
 
 
 async def market_context() -> dict:
@@ -21,8 +20,8 @@ async def market_context() -> dict:
     - menu_items: fetched from coop internal API
     - cart_count/cart_total: fetched from cart internal API
     """
-    from shared.context import base_context
-    from shared.internal_api import get as api_get, dictobj
+    from shared.infrastructure.context import base_context
+    from shared.infrastructure.internal_api import get as api_get, dictobj
 
     ctx = await base_context()
 
@@ -44,9 +43,9 @@ async def market_context() -> dict:
 
 def create_app() -> "Quart":
     from models.market_place import MarketPlace
-    from models.ghost_content import Post
+    from blog.models.ghost_content import Post
 
-    app = create_base_app("market", context_fn=market_context, before_request_fns=[load_cart])
+    app = create_base_app("market", context_fn=market_context)
 
     # App-specific templates override shared templates
     app_templates = str(Path(__file__).resolve().parent / "templates")
@@ -111,12 +110,13 @@ def create_app() -> "Quart":
             },
         }
 
-        # Load market scoped to post
+        # Load market scoped to post (container pattern)
         market = (
             await g.s.execute(
                 select(MarketPlace).where(
                     MarketPlace.slug == market_slug,
-                    MarketPlace.post_id == post.id,
+                    MarketPlace.container_type == "page",
+                    MarketPlace.container_id == post.id,
                     MarketPlace.deleted_at.is_(None),
                 )
             )
@@ -135,16 +135,24 @@ def create_app() -> "Quart":
     # --- Root route: market listing ---
     @app.get("/")
     async def markets_listing():
-        from sqlalchemy.orm import selectinload
-
-        markets = (
+        rows = (
             await g.s.execute(
-                select(MarketPlace)
+                select(MarketPlace, Post)
+                .join(
+                    Post,
+                    (MarketPlace.container_type == "page")
+                    & (MarketPlace.container_id == Post.id),
+                )
                 .where(MarketPlace.deleted_at.is_(None))
-                .options(selectinload(MarketPlace.post))
                 .order_by(MarketPlace.name)
             )
-        ).scalars().all()
+        ).all()
+
+        # Attach the joined post to each market for template access
+        markets = []
+        for market, post in rows:
+            market.page = post
+            markets.append(market)
 
         html = await render_template(
             "_types/market/markets_listing.html",