Replaces the tab approach with a dedicated 'Missing Data' module in the
sidebar. The module has two sub-tabs: 'Missing Classification' and
'Missing Launch Date'. Shows SKU, Name, Classification, Launch Date and
Ready to Order columns. Includes a local Excel serial date formatter so
dates that slipped through the App.tsx pre-processing are rendered
correctly instead of showing as raw numbers.
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
Christian Vidal WolfandClaude Sonnet 4.6