feat(D): Phase D — Undo/Restore komplett implementiert

- D-GEN: RestoreRegistry mit RestoreConfig (model_class, restore_permission, excluded_fields, special_handler)
- D-HOOK: history_hooks.py mit register_history_hooks() für after_create/update/delete
- D-CORE: Company create+update record_history in companies.py
- D-PLUG: Task/Calendar/DMS record_history in services/routes
- D-SOFT: Alle registrierten Entitäten haben deleted_at + un-delete via Registry
- D-MAIL: Mail special_handler (IMAP Trash-Move, Folder-Verify) + record_history in delete/move
- D-TRASH: GET /entity-history/trash (filterbar, paginiert) + Frontend Trash.tsx
- D-TOAST: UndoToast.tsx (5s Auto-Dismiss, useUndoToast Hook)
- D-HIST-UI: HistoryPanel.tsx (Timeline, Diff-View, Restore-Button)
- D-BULK: POST /entity-history/bulk-restore mit partial_success Semantik
- D-RET: POST /entity-history/retention/archive (GDPR hard-delete >90 Tage)
- D-TEST: 26 Tests in test_restore_registry.py, alle grün
- D-DOC: test-strategy.md + security_kernel.md aktualisiert

Backend: 10 Dateien, Frontend: 7 Dateien, Tests: 1 Datei, Docs: 3 Dateien
26/26 Tests passed, TSC 0 errors, App import 492 routes

app/core/history_hooks.py

@@ -0,0 +1,180 @@
+"""Hook-based history recording — standard hooks that call record_history().
+
+Registers action hooks for entity lifecycle events:
+- entity.after_create  → record_history(action='create', snapshot_after=...)
+- entity.after_update  → record_history(action='update', snapshot_before=..., snapshot_after=..., changes=...)
+- entity.after_delete  → record_history(action='delete', snapshot_before=...)
+
+Plugins can register their own entity types by calling:
+    register_history_hooks(reg, 'task', 'task.after_create', 'task.after_update', 'task.after_delete')
+
+This is explicit, traceable, and testable — no SQLAlchemy event listeners.
+"""
+
+from __future__ import annotations
+
+import logging
+import uuid
+from typing import Any
+
+from sqlalchemy.ext.asyncio import AsyncSession
+
+from app.core.hooks import HookRegistry, get_hook_registry
+from app.services.entity_history_service import record_history
+
+logger = logging.getLogger(__name__)
+
+
+def register_history_hooks(
+    reg: HookRegistry,
+    entity_type: str,
+    after_create_hook: str,
+    after_update_hook: str,
+    after_delete_hook: str,
+) -> None:
+    """Register standard history-recording hooks for an entity type.
+
+    Each hook receives kwargs: db, tenant_id, user_id, and either:
+    - after_create: snapshot_after (the created entity dict)
+    - after_update: snapshot_before, snapshot_after, changes
+    - after_delete: snapshot_before
+    """
+
+    async def _on_create(
+        snapshot_after: dict[str, Any],
+        *,
+        db: AsyncSession,
+        tenant_id: uuid.UUID,
+        user_id: uuid.UUID | None = None,
+        **kwargs: Any,
+    ) -> None:
+        entity_id = _extract_entity_id(snapshot_after)
+        if entity_id is None:
+            logger.warning("history_hooks: cannot extract entity_id from snapshot for %s", entity_type)
+            return
+        await record_history(
+            db, tenant_id, user_id, entity_type, entity_id,
+            action="create", snapshot_after=snapshot_after,
+        )
+
+    async def _on_update(
+        snapshot_after: dict[str, Any],
+        *,
+        db: AsyncSession,
+        tenant_id: uuid.UUID,
+        user_id: uuid.UUID | None = None,
+        snapshot_before: dict[str, Any] | None = None,
+        changes: dict[str, Any] | None = None,
+        **kwargs: Any,
+    ) -> None:
+        entity_id = _extract_entity_id(snapshot_after) or (
+            _extract_entity_id(snapshot_before) if snapshot_before else None
+        )
+        if entity_id is None:
+            logger.warning("history_hooks: cannot extract entity_id for %s update", entity_type)
+            return
+        await record_history(
+            db, tenant_id, user_id, entity_type, entity_id,
+            action="update",
+            snapshot_before=snapshot_before,
+            snapshot_after=snapshot_after,
+            changes=changes,
+        )
+
+    async def _on_delete(
+        snapshot_before: dict[str, Any] | None = None,
+        *,
+        db: AsyncSession,
+        tenant_id: uuid.UUID,
+        user_id: uuid.UUID | None = None,
+        entity_id: uuid.UUID | None = None,
+        **kwargs: Any,
+    ) -> None:
+        eid = entity_id or (_extract_entity_id(snapshot_before) if snapshot_before else None)
+        if eid is None:
+            logger.warning("history_hooks: cannot extract entity_id for %s delete", entity_type)
+            return
+        await record_history(
+            db, tenant_id, user_id, entity_type, eid,
+            action="delete", snapshot_before=snapshot_before,
+        )
+
+    reg.register_action(after_create_hook, _on_create, priority=90)
+    reg.register_action(after_update_hook, _on_update, priority=90)
+    reg.register_action(after_delete_hook, _on_delete, priority=90)
+    logger.debug("History hooks registered for: %s", entity_type)
+
+
+def _extract_entity_id(snapshot: dict[str, Any] | None) -> uuid.UUID | None:
+    """Extract entity UUID from a snapshot dict."""
+    if snapshot is None:
+        return None
+    raw_id = snapshot.get("id")
+    if raw_id is None:
+        return None
+    if isinstance(raw_id, uuid.UUID):
+        return raw_id
+    try:
+        return uuid.UUID(str(raw_id))
+    except (ValueError, TypeError):
+        return None
+
+
+def register_default_history_hooks() -> None:
+    """Register history hooks for all built-in entity types.
+
+    Called during app startup after the hook registry is initialized.
+    Plugin entities should register their own hooks in on_activate().
+    """
+    reg = get_hook_registry()
+
+    # Contact (already has manual record_history calls in contact_service.py,
+    # but registering hooks ensures consistency for any code path that fires
+    # the hooks without calling record_history directly)
+    register_history_hooks(
+        reg, "contact",
+        "contact.after_create",
+        "contact.after_update",
+        "contact.after_delete",
+    )
+
+    # Task plugin
+    register_history_hooks(
+        reg, "task",
+        "task.after_create",
+        "task.after_update",
+        "task.after_delete",
+    )
+
+    # Calendar plugin — CalendarEntry
+    register_history_hooks(
+        reg, "calendar_entry",
+        "calendar_entry.after_create",
+        "calendar_entry.after_update",
+        "calendar_entry.after_delete",
+    )
+
+    # DMS plugin — File metadata
+    register_history_hooks(
+        reg, "dms_file",
+        "dms_file.after_create",
+        "dms_file.after_update",
+        "dms_file.after_delete",
+    )
+
+    # Mail plugin
+    register_history_hooks(
+        reg, "mail",
+        "mail.after_create",
+        "mail.after_update",
+        "mail.after_delete",
+    )
+
+    logger.info("Default history hooks registered for: contact, task, calendar_entry, dms_file, mail")
+
+
+def reset_history_hooks_for_testing() -> None:
+    """Clear all history hooks — for unit tests only."""
+    reg = get_hook_registry()
+    # The hook registry's _reset_for_testing clears everything
+    reg._reset_for_testing()