The scan is the expensive part (minutes on cloud mounts), so a workspace is now
portable between browsers/machines without re-scanning:
- Per-workspace "Export" downloads the snapshot + classify map as one
<name>.zddc-workspace.json (the source-directory handle is omitted — it can't
be serialized across browsers).
- Landing-page "Import" recreates the workspace from that JSON; the user clicks
"Connect directory" once on the new browser to re-attach the folder (no
re-scan — the snapshot carries the 2-hour walk). A classification-dataset JSON
is rejected with a pointer to the in-app Import.
Also fix the welcome screen clipping its top on short viewports: the base
.empty-state centers with align-items:center, which overflows symmetrically and
puts the card's top out of scroll reach. Center the inner card with auto margins
instead — they collapse when it's taller than the viewport, keeping the top
reachable.
Test: workspace import recreates a transferable record (snapshot + map, no handle); 46 green.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>