fix: honor theme-specific embedded icon colors

[vycdev2]

Summary

• make embedded todo type icons use todo.colors.dark.types and todo.colors.light.types in the matching theme
• preserve todo.colors.types as the fallback for either theme
• add regression coverage and document the fix

Verification

• npm run check — passed: type checking, 402 tests, development compilation, and Prettier checks
• git diff --check — passed

Risk

• Low: the change is limited to generated embedded-view type icons and retains the existing base color when no theme override is configured.

This was generated by an AI agent (vycdev2). Please verify any changes before merging or applying.