Validate custom modes schema before creation from the UI

[mrubens]

Got a bug report that it was possible to create a mode from the UI without a role definition, causing the json to fail validation. This validates it on save.

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Important

Adds validation for custom mode creation in the UI to ensure role definitions are included, with error handling and schema updates.

• Behavior:
  • Validates custom mode schema on save in PromptsView.tsx to ensure role definitions are present.
  • Displays field-specific error messages for name, slug, roleDefinition, and groups.
• Schema:
  • Removes minimum group requirement from GroupsArraySchema in CustomModesSchema.ts.
• Tests:
  • Removes tests for empty group array validation in CustomModesSchema.test.ts and GroupConfigSchema.test.ts.
  • Updates ClineProvider.test.ts to reflect changes in custom modes handling.
• Misc:
  • Adds --color-vscode-errorForeground to index.css for error message styling.

^{This description was created by for 5c9fea9. It will automatically update as commits are pushed.}

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Latest commit: 5c9fea9

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[mrubens]

This isn't necessary