Summary

Add a removable Text Transform control to the Typography settings panel,
following the same add/remove pattern as the existing Underline control.

Changes

• Add "Transform" option to the Typography "+" dropdown menu
• Add Transform row with a select (uppercase, lowercase, capitalize, normal-case) and an "x" remove button
• Default to "uppercase" when first added
• Removing clears the textTransform design property

Test plan

• Open Typography settings, click "+" — see "Transform" option
• Click "Transform" — row appears with "Uppercase" selected by default
• Change value via select dropdown — class updates on the layer
• Click "x" to remove — transform row disappears, class is removed
• "+" dropdown shows "Transform" disabled while it is active