feat: add Files view comment visibility setting

[vycdev2]

Summary

• add a dedicated todo.file.view.showComments setting for optionally showing note lines in the Todo files view
• stop coupling Todo file notes to the Embedded view comment setting
• document and test the independent setting

Verification

• npm test — passed: 265 tests
• npm run compile — passed
• npm run format:check — passed
• git diff --check — passed

Risk

• Low: the new setting defaults to false, preserving existing Todo files view behavior while removing cross-view configuration coupling.

Closes #15

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