Import Bank Statement

Import one exported bank statement into the reconciliation inbox (AP-111).

Vendor-free by design: every Italian bank exports a CSV, so the first import path is a file the user already has rather than an open-banking contract we do not hold. The parser detects columns by role against alias sets, so an export shape nobody has seen still imports as long as it carries a date and an amount (or an entrate/uscite pair).

Re-importing an overlapping statement is a no-op, which is the property that makes this usable at all — home banking has no stable per-row id and every export overlaps the last one. The store's UNIQUE(user_id, booked_date, amount, details_hash) decides it with ON CONFLICT DO NOTHING, so a second upload of the same month cannot reset a match_status the user has already set. The response counts what that produced instead of hiding it: already_present is how the UI says "you have imported this before".

200 rather than 201: a re-import legitimately creates nothing, and the body is a report about a file rather than a resource at a new URL.

A file with no recognisable header is a 422 carrying the parser's own message, which names the columns it did find — the only form of "unsupported export" that a user can act on. Individual unreadable rows are never a failure: a running-balance footer is the normal case, and those come back counted in skipped.

Carries its own limiter rather than the shared write bucket: one call here is a whole statement, so it is bounded per file (bytes, rows) and per minute.