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

Phase 1-3 of decoupling:
- path_setup.py adds project root to sys.path
- Events-owned models in events/models/ (calendars with all related models)
- All imports updated: shared.infrastructure, shared.db, shared.browser, etc.
- Calendar uses container_type/container_id instead of post_id FK
- CalendarEntryPost uses content_type/content_id (generic content refs)

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

bp/calendar_entry/services/post_associations.py

@@ -5,7 +5,7 @@ from sqlalchemy import select
 from sqlalchemy.sql import func
 
 from models.calendars import CalendarEntry, CalendarEntryPost
-from models.ghost_content import Post
+from blog.models.ghost_content import Post
 
 
 async def add_post_to_entry(
@@ -38,7 +38,8 @@ async def add_post_to_entry(
     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 add_post_to_entry(
     # 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()
@@ -70,7 +72,8 @@ async def remove_post_from_entry(
     association = 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)
         )
     )

bp/calendar_entry/services/ticket_operations.py

@@ -9,6 +9,7 @@ from sqlalchemy.ext.asyncio import AsyncSession
 from models.calendars import CalendarEntry
 
 
+
 async def update_ticket_config(
     session: AsyncSession,
     entry_id: int,