Uploads now show a review page with three summary cards (valid,
duplicates, invalid), tables for invalid and duplicate rows, and a
sample of the first 20 valid rows. Nothing is written to the database
until the user clicks "Looks good — submit N contacts".
Duplicate detection treats two rows as the same contact if they share
the same pair of (callsign, grid) tuples (direction-agnostic), the
same band, and timestamps within 60 minutes. Dedup runs against both
existing DB contacts (single band/time-scoped query) and earlier rows
in the same upload, and the preview labels which side matched.
CsvImport grows preview/2 + commit/1; the old import/2 is kept as a
thin backward-compat wrapper that skips dedup. Added 11 new CsvImport
tests and reworked the SubmitLive CSV tests for the two-step flow.
Graham McIntire
44b169b234