feat: Implement AI Knowledge Sync Utilities and RAGFlow Service

- Added `aiknowledge_sync_utils.py` for provider-agnostic synchronization logic for CAIKnowledge entities, supporting both xAI and RAGFlow.
- Introduced lifecycle management for CAIKnowledge entities including states: new, active, paused, and deactivated.
- Implemented change detection using Blake3 hash for efficient document synchronization.
- Created `ragflow_service.py` to handle dataset and document management with RAGFlow API.
- Added daily cron job in `aiknowledge_daily_cron_step.py` to synchronize active CAIKnowledge entities with unclean or failed statuses.
- Developed `aiknowledge_sync_event_step.py` to process synchronization events from webhooks and cron jobs.

services/xai_upload_utils.py

@@ -209,3 +209,106 @@ class XAIUploadUtils:
             })
         except Exception as e:
             self._log.warn(f"  ⚠️  Could not remove from xAI: {e}")
+
+
+class XAIProviderAdapter:
+    """
+    Adapter der XAIService auf das Provider-Interface bringt,
+    das AIKnowledgeSyncUtils erwartet.
+
+    Interface (identisch mit RAGFlowService):
+      ensure_dataset(name, description) -> dict mit 'id'
+      list_documents(dataset_id)        -> list[dict] mit 'id', 'name'
+      upload_document(dataset_id, file_content, filename, mime_type,
+                      blake3_hash, espocrm_id, description,
+                      advoware_art, advoware_bemerkung)  -> dict mit 'id'
+      update_document_meta(dataset_id, doc_id, ...)      -> None
+      remove_document(dataset_id, doc_id)                -> None
+      delete_dataset(dataset_id)                         -> None
+      is_mime_type_supported(mime_type)                  -> bool
+    """
+
+    def __init__(self, ctx=None):
+        from services.xai_service import XAIService
+        from services.logging_utils import get_service_logger
+        self._xai = XAIService(ctx)
+        self._log = get_service_logger('xai_adapter', ctx)
+
+    async def ensure_dataset(self, name: str, description: str = '') -> dict:
+        """Erstellt oder verifiziert eine xAI Collection. Gibt {'id': collection_id} zurueck."""
+        existing = await self._xai.get_collection_by_name(name)
+        if existing:
+            col_id = existing.get('collection_id') or existing.get('id')
+            return {'id': col_id, 'name': name}
+        result = await self._xai.create_collection(name=name)
+        col_id = result.get('collection_id') or result.get('id')
+        return {'id': col_id, 'name': name}
+
+    async def list_documents(self, dataset_id: str) -> list:
+        """Listet alle Dokumente in einer xAI Collection auf."""
+        raw = await self._xai.list_collection_documents(dataset_id)
+        return [{'id': d.get('file_id'), 'name': d.get('filename')} for d in raw]
+
+    async def upload_document(
+        self,
+        dataset_id: str,
+        file_content: bytes,
+        filename: str,
+        mime_type: str = 'application/octet-stream',
+        blake3_hash=None,
+        espocrm_id=None,
+        description=None,
+        advoware_art=None,
+        advoware_bemerkung=None,
+    ) -> dict:
+        """Laedt Dokument in xAI Collection mit Metadata-Fields."""
+        fields_raw = {
+            'document_name': filename,
+            'espocrm_id': espocrm_id or '',
+            'description': description or '',
+            'advoware_art': advoware_art or '',
+            'advoware_bemerkung': advoware_bemerkung or '',
+        }
+        if blake3_hash:
+            fields_raw['blake3_hash'] = blake3_hash
+        fields = {k: v for k, v in fields_raw.items() if v}
+
+        file_id = await self._xai.upload_to_collection(
+            collection_id=dataset_id,
+            file_content=file_content,
+            filename=filename,
+            mime_type=mime_type,
+            fields=fields,
+        )
+        return {'id': file_id, 'name': filename}
+
+    async def update_document_meta(
+        self,
+        dataset_id: str,
+        doc_id: str,
+        blake3_hash=None,
+        description=None,
+        advoware_art=None,
+        advoware_bemerkung=None,
+    ) -> None:
+        """
+        xAI unterstuetzt kein PATCH fuer Metadaten.
+        Re-Upload wird vom Caller gesteuert (via syncedMetadataHash Aenderung
+        fuehrt zum vollstaendigen Upload-Path).
+        Hier kein-op.
+        """
+        self._log.warn(
+            "XAIProviderAdapter.update_document_meta: xAI unterstuetzt kein "
+            "Metadaten-PATCH – kein-op. Naechster Sync loest Re-Upload aus."
+        )
+
+    async def remove_document(self, dataset_id: str, doc_id: str) -> None:
+        """Loescht Dokument aus xAI Collection (Datei bleibt in xAI Files API)."""
+        await self._xai.remove_from_collection(dataset_id, doc_id)
+
+    async def delete_dataset(self, dataset_id: str) -> None:
+        """Loescht xAI Collection."""
+        await self._xai.delete_collection(dataset_id)
+
+    def is_mime_type_supported(self, mime_type: str) -> bool:
+        return self._xai.is_mime_type_supported(mime_type)