* feat: expand terminal quick keys
Add navigation keys plus ctrl/alt modifiers for the web terminal.
* feat: make terminal modifiers sticky
Keep Ctrl/Alt active until toggled off, Termux-style.
* style: improve terminal quick key buttons
Boost active contrast and adjust sizing for mobile.
* feat: add terminal key popups
Use long-press popups for / and - keys.
* fix: make terminal modifiers mutually exclusive
* fix(web): keep soft keyboard open on terminal buttons
* fix(web): allow mouse clicks on terminal quick keys
* refactor(web): simplify terminal quick input modifier handling
Remove the applyModifiers callback and inline modifier state application.
Add automatic modifier reset after quick input when appropriate.
* refactor(web): extract dispatchSequence helper for terminal input handling
Create a reusable dispatchSequence callback to handle modifier application
and reset logic for both terminal data input and quick input handlers.
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Co-authored-by: weishu <twsxtd@gmail.com>
