Debounce popup accelerators while the user is typing

Summary

Codex should debounce or suppress simple popup accelerators while the user is actively typing into a prompt or text field.

Right now, popup shortcuts can keep flashing or competing for attention on each keystroke, which makes the UI feel interrupted or partially locked instead of respecting text-entry focus.

Problem

Popup surfaces that use simple accelerators (A, B, C, 1, 2, 3, _, etc.) are too eager during active typing.

While entering prompt text, each keystroke can re-trigger popup affordances or visual emphasis. The result is attention hijacking: the popup appears to demand punctuation or action even though the user is just writing.

Requested behavior

• Add a global popup accelerator debouncer that any popup can depend on
• When the user is typing in a prompt/text field, require a 250 ms idle gap before popup accelerators may consume simple keys
• During the suppression window, popup visuals should telegraph that accelerators are temporarily gated rather than repeatedly flashing on each key
• Text-entry focus should win over popup accelerators by default

Success criteria

• Typing continuously into a prompt does not trigger popup options bound to plain keys
• After 250 ms of typing inactivity, popup accelerators become eligible again
• The UI clearly indicates the temporary suppression state instead of flashing/stealing attention
• The behavior applies through a shared/global mechanism, not per-popup one-offs