🎨 Palette: Add native typing audio feedback to custom terminal accessory keys

[emkey1]

💡 What: Implemented UIInputViewAudioFeedback on the custom terminal accessory bar and bound UIDevice.current.playInputClick() to the .touchDown events of the keys.
🎯 Why: Custom UIInputView keys default to being silent, making the terminal's top row feel non-native and detached from the standard iOS keyboard below it.
♿ Accessibility: Honors system-level keyboard click settings seamlessly by relying on native APIs.
📓 Learning: Recorded insight in .Jules/palette.md for future custom keyboard implementations.

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PR created automatically by Jules for task 6797571852848488829 started by @emkey1

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