Extracts the mass-import block from +page.svelte into ImportStatusCard.svelte.
Changes per the three UX fixes from issue #533:
- RUNNING: animated spinner (animate-spin) + processed count at text-base;
auto-poll at 2 s was already in place
- DONE: processed count at text-base, label at text-xs uppercase tracking-widest
- FAILED: maps statusCode (IMPORT_FAILED_NO_SPREADSHEET / IMPORT_FAILED_INTERNAL)
to Paraglide messages — no raw German backend string rendered
Adds vitest-browser tests covering spinner visibility, count display,
and per-statusCode FAILED message selection.
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
