Flexible configuration for submit and new line actions

### Describe the feature or problem you'd like to solve

A way to define what combinations do a submit or a new line

### Proposed solution

Currently it is possible to configure SHIFT+ENTER as new line but ENTER always stays as submit.
More tools are allowing or adopting the CMD+ENTER as submit to avoid accidental submits.
Having this possibility in copilot would help avoiding accident submits.

### Example prompts or workflows

_No response_

### Additional context

_No response_

該 issue 未指定檔案或測試；請先追蹤 CLI 輸入路徑中現有的使用 SHIFT+ENTER 換行的設定，以及使用 ENTER 提交的處理邏輯。定義應如何設定提交和換行組合，然後新增涵蓋範圍，展示所選組合能夠正常運作且不會意外提交。

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