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

Phase 1-3 of decoupling:
- path_setup.py adds project root to sys.path
- Blog-owned models in blog/models/ (ghost_content, snippet, tag_group)
- Re-export shims for shared models (user, kv, magic_link, menu_item)
- All imports updated: shared.infrastructure, shared.db, shared.browser, etc.
- No more cross-app post_id FKs in calendar/market/page_config

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

bp/post/services/entry_associations.py

@@ -4,7 +4,7 @@ from sqlalchemy.ext.asyncio import AsyncSession
 from sqlalchemy import select
 from sqlalchemy.sql import func
 
-from models.calendars import CalendarEntry, CalendarEntryPost, Calendar
+from events.models.calendars import CalendarEntry, CalendarEntryPost, Calendar
 from models.ghost_content import Post
 
 
@@ -35,7 +35,8 @@ async def toggle_entry_association(
     existing = await session.scalar(
         select(CalendarEntryPost).where(
             CalendarEntryPost.entry_id == entry_id,
-            CalendarEntryPost.post_id == post_id,
+            CalendarEntryPost.content_type == "post",
+            CalendarEntryPost.content_id == post_id,
             CalendarEntryPost.deleted_at.is_(None)
         )
     )
@@ -49,7 +50,8 @@ async def toggle_entry_association(
         # Create association
         association = CalendarEntryPost(
             entry_id=entry_id,
-            post_id=post_id
+            content_type="post",
+            content_id=post_id
         )
         session.add(association)
         await session.flush()
@@ -67,7 +69,8 @@ async def get_post_entry_ids(
     result = await session.execute(
         select(CalendarEntryPost.entry_id)
         .where(
-            CalendarEntryPost.post_id == post_id,
+            CalendarEntryPost.content_type == "post",
+            CalendarEntryPost.content_id == post_id,
             CalendarEntryPost.deleted_at.is_(None)
         )
     )
@@ -88,7 +91,8 @@ async def get_associated_entries(
     entry_ids_result = await session.execute(
         select(CalendarEntryPost.entry_id)
         .where(
-            CalendarEntryPost.post_id == post_id,
+            CalendarEntryPost.content_type == "post",
+            CalendarEntryPost.content_id == post_id,
             CalendarEntryPost.deleted_at.is_(None)
         )
     )

bp/post/services/markets.py

@@ -6,10 +6,10 @@ import unicodedata
 from sqlalchemy import select
 from sqlalchemy.ext.asyncio import AsyncSession
 
-from models.market_place import MarketPlace
+from market.models.market_place import MarketPlace
 from models.ghost_content import Post
-from models.page_config import PageConfig
-from suma_browser.app.utils import utcnow
+from cart.models.page_config import PageConfig
+from shared.browser.app.utils import utcnow
 
 
 class MarketError(ValueError):
@@ -43,14 +43,14 @@ async def create_market(sess: AsyncSession, post_id: int, name: str) -> MarketPl
         raise MarketError("Markets can only be created on pages, not posts.")
 
     pc = (await sess.execute(
-        select(PageConfig).where(PageConfig.post_id == post_id)
+        select(PageConfig).where(PageConfig.container_type == "page", PageConfig.container_id == post_id)
     )).scalar_one_or_none()
     if pc is None or not (pc.features or {}).get("market"):
         raise MarketError("Market feature is not enabled for this page. Enable it in page settings first.")
 
     # Look for existing (including soft-deleted)
     existing = (await sess.execute(
-        select(MarketPlace).where(MarketPlace.post_id == post_id, MarketPlace.slug == slug)
+        select(MarketPlace).where(MarketPlace.container_type == "page", MarketPlace.container_id == post_id, MarketPlace.slug == slug)
     )).scalar_one_or_none()
 
     if existing:
@@ -61,7 +61,7 @@ async def create_market(sess: AsyncSession, post_id: int, name: str) -> MarketPl
             return existing
         raise MarketError(f'Market with slug "{slug}" already exists for this page.')
 
-    market = MarketPlace(post_id=post_id, name=name, slug=slug)
+    market = MarketPlace(container_type="page", container_id=post_id, name=name, slug=slug)
     sess.add(market)
     await sess.flush()
     return market
@@ -71,7 +71,8 @@ async def soft_delete_market(sess: AsyncSession, post_slug: str, market_slug: st
     market = (
         await sess.execute(
             select(MarketPlace)
-            .join(Post, MarketPlace.post_id == Post.id)
+            .join(Post, MarketPlace.container_id == Post.id)
+            .where(MarketPlace.container_type == "page")
             .where(
                 Post.slug == post_slug,
                 MarketPlace.slug == market_slug,