#7527 feat(editor): replace canonical input toggle with icon switch

Summary

• Replace the canonical input mode arrow with explicit Selector and Variable icon choices across subblocks and nested tool parameters.
• Use a shared, keyboard-accessible icon switch with optional tooltips, disabled states, and a transparent unselected background.

Type of Change

• Bug fix
• New feature
• Breaking change
• Documentation
• Other: ___________

Testing

• IconSwitch tests: 4 passed.
• App TypeScript check passed.
• Scoped Biome check and API validation audit passed.
• Verified selection, hover tooltips, cursor, and nested field rendering in Chrome.
• Review focus: selection behavior, disabled states, keyboard access, and consistent rendering across canonical inputs.

Checklist

• Code follows project style guidelines
• Self-reviewed my changes
• Tests added/updated and passing
• No new warnings introduced
• I confirm that I have read and agree to the terms outlined in the Contributor License Agreement (CLA)

Screenshots/Videos

Before:

After: