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_entries/routes.py

@@ -11,18 +11,20 @@ from sqlalchemy import update
 
 from models.calendars import CalendarEntry
 
+
 from .services.entries import (
 
     add_entry as svc_add_entry,
 )
-from suma_browser.app.authz import require_admin
-from suma_browser.app.redis_cacher import clear_cache
+from shared.browser.app.authz import require_admin
+from shared.browser.app.redis_cacher import clear_cache
 
 
-from suma_browser.app.bp.calendar_entry.routes import register as register_calendar_entry
+from bp.calendar_entry.routes import register as register_calendar_entry
 
 
 from models.calendars import CalendarSlot
+
 from sqlalchemy import select
 
 

bp/calendar_entries/services/entries.py

@@ -7,9 +7,10 @@ from sqlalchemy import select, and_, or_
 from sqlalchemy.ext.asyncio import AsyncSession
 
 from models.calendars import Calendar, CalendarEntry
+
 from datetime import datetime
 
-from suma_browser.app.errors import AppError
+from shared.browser.app.errors import AppError
 
 class CalendarError(AppError):
     """Base error for calendar service operations."""
@@ -120,7 +121,8 @@ async def list_entries(
         await sess.execute(
             select(Calendar.id)
             .where(
-                Calendar.post_id == post_id,
+                Calendar.container_type == "page",
+                Calendar.container_id == post_id,
                 Calendar.slug == calendar_slug,
                 Calendar.deleted_at.is_(None),
             )