[Import] Previously cleansed dataset silently replaces a newly uploaded file

[Exotic209093]

Severity

Critical — the file shown on screen is not the file that gets pushed.

What happens

DataPushScreen computes sourceRecords = props.cleanedRecords ?? dataset?.sourceRecords. The Cleanser route clears cleaned on dataset change, but the Import route's onDataset={setDataset} never calls setCleaned(null). Clean file A once, return to Import, upload file B: the banner shows B's filename and B's headers drive the mapping UI, but every record mapped and pushed comes from file A's cleaned rows. The same override corrupts the Retry and "Prepare Delete Push" flows, which also load datasets via onDataset.

Evidence

• src/ui/app/AppRoot.tsx:402 (import route, no cleaned reset) vs :462 (cleanser route resets)
• src/ui/screens/DataPushScreen.tsx:163

Suggested fix

Clear cleaned in the import route's onDataset callback (and whenever dataset.filename changes).

Environment

Commit 74cf21b (main), WaveLink 0.6.0. Found in the 2026-08-31 adversarial audit (code-verified).