Two bugs caused a FK constraint violation on products.unit:
1. RecognizedItem.fromJson fell back to 'шт' (Cyrillic, not a valid
units.code) when the AI returned a null unit — changed to 'pcs'.
2. The unit dropdown in RecognitionConfirmScreen displayed units.keys.first
for invalid units but never updated item.unit, so the invalid value was
still submitted. Added a reconcile step in build() that syncs item.unit
to units.keys.first whenever the stored value is not in the valid set.
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
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