Rebuilt on top of dev's RFC #883 state-machine UI rather than the now-defunct
StoredFile shape:
- Extend StoredFileInfo with fileName/size/uploadedAt/isUserUpload
- Populate metadata from on-disk stats in RagService.getStoredFiles
- Add fileSourceSchema validator + getFileContent/downloadFile endpoints
scoped to the uploads directory only (tighter than the original PR — matches
docs_service traversal pattern)
- KnowledgeBaseModal: sortable Size and Uploaded columns; View/Download
buttons on upload-bucket rows; new FileViewerModal for in-browser text
preview. Bucket grouping preserved — sort applies within each bucket.
- Use formatBytes from ~/lib/util rather than redefining
51ea98e554