513b191e47
Backend foundation for the upcoming Downloads modal refresh. Adds three
helpers on GalleryDLService:
_compute_run_stats exit_code + downloaded/skipped/per-item-failure/
warning counts, derived from stdout+stderr
_extract_errors_warnings filters stderr to just [error]/[warning] lines
so the modal can show a concise errors-only view
_truncate_log caps a log string (default 500KB) with head+tail+
elision marker, preventing verbose multi-hour runs
from bloating the download_sessions JSONB
Wires all three into download.metadata_ in the download task. No schema
change — everything nests into the existing metadata JSONB column.
Follow-up PR will consume these fields in the Downloads.vue modal.