Prevent Todo shortcuts from firing during shortcut recording

[culpen90]

Summary

• Suspend Toggle Todo and Reflow Todo bindings while a shortcut field is recording.
• Prevent Todo settings changes from restoring those bindings during recording.
• Restore only bindings allowed by the current Todo and Todo Mode state.
• Add regression coverage for suspension and state-aware restoration.

Context

Window-action bindings are already suspended during shortcut recording. Todo shortcuts use separate MASShortcut registrations, so they could remain active and trigger Rectangle behavior while a new shortcut was being entered.

Testing

• Focused shortcut-recording suite: 6 tests passed.
• Full suite comparison: this branch and a clean checkout of current upstream main report the same 21 unrelated cooperative-resize assertion failures. The branch adds three passing tests, for 173 total tests versus 170 on the upstream baseline.

Fixes #195