Elicitation: Enter key selects but doesn't accept/submit the choice

[m-nash]

Problem

Follow-up to #1863 — the fix made Enter "select" the highlighted choice, but it doesn't "accept" (submit) it. The user still has to press Ctrl+S after pressing Enter, which defeats the purpose.

Expected Behavior

Enter should work the same way it does when Copilot itself asks the user a question via ask_user — pressing Enter on the highlighted choice should accept it and submit the form in one step.

Having to press Ctrl+S for elicitations but Enter for Copilot's own questions feels inconsistent and unnatural.

Use Case

Same as #1863 — an MCP server presents an enum selector via elicitation/create. The user navigates to their choice and presses Enter expecting it to be submitted, but instead they must also press Ctrl+S.

Environment

• Copilot CLI v0.0.423
• Windows, PowerShell
• MCP elicitation with enum-only schema