Fetch Paperless before wiping the index in reindex

`reindex` deleted every chunk before contacting Paperless, so an unreachable
or empty Paperless left the store empty (which happened when Paperless was
crash-looping during its v3 upgrade). It now fetches first, aborts without
deleting if that fails or returns nothing, and indexes the fetched documents
instead of fetching twice.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

scripts/manage_vectorstore.py

@@ -8,6 +8,7 @@ import sys
 from blueprints.rag.logic import (
     delete_all_documents,
     delete_documents_by_metadata,
+    fetch_documents_from_paperless_ngx,
     get_vector_store_stats,
     index_documents,
     index_obsidian_documents,
@@ -33,11 +34,23 @@ async def index():
 
 
 async def reindex():
-    """Clear and reindex everything: Paperless documents and the Obsidian vault."""
+    """Clear and reindex everything: Paperless documents and the Obsidian vault.
+
+    Paperless is fetched before anything is deleted, so an unreachable or
+    empty Paperless leaves the existing index untouched.
+    """
+    print("Fetching documents from Paperless-NGX...")
+    documents = await fetch_documents_from_paperless_ngx()
+    if not documents:
+        raise RuntimeError(
+            "Paperless returned no documents to index; leaving the index untouched"
+        )
+    print(f"Fetched {len(documents)} documents")
     print("Clearing existing documents...")
     delete_all_documents()
     print("Cleared")
-    await index()
+    await index_documents(documents)
+    print("Paperless indexing complete!")
     await reindex_obsidian(clear=False)