coding-agent: update theme-schema.json to match latest theme implementation (#763)
* feat(coding-agent): update theme-schema.json
Added to required/properties:
- thinkingText - thinking block text color
- selectedBg - selected item background
- toolTitle - tool execution box title (replaces toolText)
- toolOutput - tool execution box output text
- mdLinkUrl - markdown link URL color
- thinkingOff, thinkingMinimal, thinkingLow, thinkingMedium, thinkingHigh, thinkingXhigh, bashMode added to required array (were already in properties)
Removed:
- toolText (replaced by toolTitle and toolOutput)
* removed thinking* border colors from required