refactor(#356): DSAR-Fachlogik vollstaendig aus dem Core extrahiert — dsar_collect/dsar_erase in die 5 beteiligten Contracts (contacts, mail, tasks, calendar, kommunikation); core/jobs.py sammelt/loescht nur Core-eigene Daten und iteriert generisch ueber die Plugin-Registry; neue Plugins liefern DSAR-Kategorien ohne Core-Aenderung; Counts-/Category-Keys unveraendert; tasks/contracts.py von Patch-Artefakt bereinigt

fixes #356

app/plugins/builtins/calendar/contracts.py

@@ -2,6 +2,11 @@
 
 from __future__ import annotations
 
+from typing import Any
+
+from sqlalchemy import select
+from sqlalchemy.ext.asyncio import AsyncSession
+
 from app.plugins.builtins.calendar.models import Calendar, CalendarEntry, CalendarEntryLink
 from app.plugins.builtins.contracts import get_contract_registry
 
@@ -15,6 +20,33 @@ class CalendarContract:
     CalendarEntry = CalendarEntry
     CalendarEntryLink = CalendarEntryLink
 
+    @staticmethod
+    async def dsar_collect(
+        db: AsyncSession, tenant_id: Any, user_id: Any
+    ) -> dict[str, Any]:
+        """GDPR Art. 15: collect calendar entries owned by the user."""
+        cal_entries = (
+            await db.execute(
+                select(CalendarEntry).where(
+                    CalendarEntry.tenant_id == tenant_id,
+                    CalendarEntry.owner_id == user_id,
+                    CalendarEntry.deleted_at.is_(None),
+                ).limit(1000)
+            )
+        ).scalars().all()
+        return {
+            "calendar_entries": [
+                {
+                    "id": str(e.id),
+                    "title": e.title,
+                    "entry_type": e.entry_type,
+                    "start_at": e.start_at.isoformat() if e.start_at else None,
+                    "end_at": e.end_at.isoformat() if e.end_at else None,
+                }
+                for e in cal_entries
+            ]
+        }
+
     @classmethod
     def get_function(cls, name: str):
         """Return a callable exposed by this contract, or None if absent."""