fix: include paperless_id in chunk references

get_all_chunk_references was missing paperless_id field needed for
Paperless orphan detection.

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Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

src/services/vector_service.py

@@ -488,6 +488,7 @@ class VectorService:
                     "chunk_id": point["id"],
                     "page_id": payload.get("page_id"),
                     "document_id": payload.get("document_id"),
+                    "paperless_id": payload.get("paperless_id"),  # For Paperless documents
                     "collection_id": payload.get("collection_id"),
                     "doc_type": payload.get("doc_type", "wiki")
                 })