Derive selection hotkeys from bracketed letters in option labels

[AlexSkrypnyk]

Summary

Add optional single-key selection shortcuts derived from a bracketed letter in an option's label.

Details

Selecting from a long list means arrowing to the target. Add optional single-key shortcuts derived from a bracketed letter in an option's label - one marked letter becomes the accelerator that jumps to and selects the option directly.

Acceptance criteria

• When enabled, a bracketed letter in an option label becomes a shortcut key.
• Pressing the key jumps to and selects that option directly.
• Two options claiming the same key are detected at setup and throw, consistent with existing key-binding conflict handling.
• The feature is interactive-only and ignored in headless collection.
• Covered by tests.