feat: webhook event-model und shared-secret auth

app/webhook/models.py

@@ -0,0 +1,14 @@
+from enum import Enum
+from pydantic import BaseModel
+
+
+class EventType(str, Enum):
+    CREATED = "created"
+    UPDATED = "updated"
+    DELETED = "deleted"
+
+
+class NextcloudEvent(BaseModel):
+    event_type: EventType
+    file_path: str
+    file_name: str