The import endpoint did all the work in one request and returned only an
aggregate summary, so the UI couldn't show progress or per-file status.
Refactor FileService.Import to take an optional progress callback and emit
a "start" event (with the total entry count), one "file" event per entry as
it finishes (index, filename, status, optional reason), and a final "done"
event with the tallies. The handler streams these as newline-delimited JSON
and flushes after each, deferring the response headers until the first event
so a validation error raised before any file is touched is still returned as
a normal JSON error.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
H1K0
129cc59793