Fix adopt_entries_for_user deleting confirmed bookings on login

The adoption logic soft-deleted ALL user entries before adopting
anonymous session entries. This nuked confirmed/ordered bookings
every time the user logged in. Add state="pending" filter so only
stale pending entries are cleared.

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

services/calendar_impl.py

@@ -376,10 +376,18 @@ class SqlCalendarService:
     async def adopt_entries_for_user(
         self, session: AsyncSession, user_id: int, session_id: str,
     ) -> None:
-        """Adopt anonymous calendar entries for a logged-in user."""
+        """Adopt anonymous calendar entries for a logged-in user.
+
+        Only deletes stale *pending* entries for the user — confirmed/ordered
+        entries must be preserved.
+        """
         await session.execute(
             update(CalendarEntry)
-            .where(CalendarEntry.deleted_at.is_(None), CalendarEntry.user_id == user_id)
+            .where(
+                CalendarEntry.deleted_at.is_(None),
+                CalendarEntry.user_id == user_id,
+                CalendarEntry.state == "pending",
+            )
             .values(deleted_at=func.now())
         )
         cal_result = await session.execute(