Why: A single run re-registering one deliverable left three identical
report files side by side (storage is append-only by design and the
prompt even teaches revisions-as-new-versions); the panel listed every
row. Per the owner ruling, storage keeps all versions - the panel now
groups by name, shows only the latest row, badges multi-version groups
with the count, and expands (Collapsible primitive) to list history
with per-version preview/download.
Evidence: tsc clean; vitest 99/99 including new grouping tests (latest
selection by updatedAt, ordering, cross-name independence, empty);
knip unchanged.
Impact: Frontend-only display logic; no storage, API, or prompt
changes.
Refs: Dev task fix/artifact-version-dedupe
weichen