c540dd4f52
- Revert search.html and files.html links back to /files/{id}
- Add GET /files/{file_id} route (file_view_page) with workdir path-
containment guards (os.path.commonpath) to prevent traversal
- Create file_view.html: document-centric page showing AI metadata,
inline PDF preview, extracted OCR text, download actions, file info,
status pill, and link to /files/{id}/detail for process pipeline view
- Existing /files/{id}/detail route is unchanged
Co-authored-by: christianlouis <361235+christianlouis@users.noreply.github.com>