DocumentSyncService._index_vectors ran delete_by_filter on the
document's existing chunks FIRST and only then embedded; if the
embedding pass failed (Ollama down) the Paperless document was left
with zero vectors until the next successful sync - the same
zero-vector hazard already fixed for wiki pages in
VectorService.update_from_page.
Chunk ids are now deterministic uuid5 (document_{id}_chunk_{i}) so
re-upserting overwrites in place; new points are upserted first, then
stale points (including legacy random-uuid4 ones) are pruned via
scroll + delete_by_ids, and only after a successful upsert.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01QbFZyDvYksazX6nYQYZ67L