Adds a new multipart endpoint that accepts multiple files and creates one
document per file without requiring any form metadata. Each document gets
title = filename-without-extension and status = UPLOADED.
- Fix storeDocument() to strip the file extension from the document title
- Validate content type (PDF/JPEG/PNG/TIFF) server-side; unsupported files
are skipped and returned as per-file errors in QuickUploadResult
- Tests cover 401/403 auth, success path, and unsupported file type
Closes#66 (backend part)
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
332b5b3c40