- Add nullable collection field to KbIngestState, propagated through the
embed job, RAG service, and Qdrant point payloads (indexed for filtering)
- Add upload-time category selection and per-file collection reassignment
in the Knowledge Base modal, with a filterable Stored Files table
- Add a 'Search in' collection filter to the chat interface, threaded
through to searchSimilarDocuments as an optional Qdrant filter
- Fix .docx extraction: previously routed through raw-text extraction
(garbage output for a ZIP-based XML format); adds a proper mammoth-based
extractor and a dedicated 'docx' file-type case
cae3dde8b4