- Upload endpoint (base64 JSON, no multipart dep): extracts text from
pdf/docx/txt/md via pypdf + python-docx, then runs the existing
chunk/embed pipeline. Documents page uploads files straight through.
- Citations: the chat stream emits an SSE `sources` event listing the
documents that fed the answer; the UI shows them as chips under the reply.
- Deps: pypdf, python-docx (both pure-Python, Windows-safe).
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>