Ask clarifying questions in chat instead of forms

Describe the feature or problem you'd like to solve

Allow agents to ask clarification questions in normal chat instead of forms, without discouraging questions or increasing agent autonomy.

Proposed solution

Add a Forms / Chat presentation preference, independent of the askUser enablement setting.
In chat mode, the agent should display clarification questions inline, wait for my reply through the regular chat input, and continue afterward. Follow-up questions should use the same conversational flow.
This should change only the presentation, preserving when and why agents ask for clarification. Forms could remain the default, with chat as an opt-in preference.

Example prompts or workflows

No response

Additional context

I previously disabled askUser to avoid the forms interface, but that does not reflect my intended preference. I still want agents to ask useful questions rather than make assumptions. I simply prefer asking and answering through the normal conversation, because the ask_user forms are limited compared to the regular chat interface.

Example for why it is not convenient to work with ask_user/forms:

まず、CLI における既存の askUser の有効化と Forms / Chat の表示動作を追跡します。完了の条件は、チャットモードで確認プロンプトを有効なままにし、質問をインラインで表示し、通常のチャット入力で返信を受け付け、既存のタイミングとフォローアップのフローを維持しつつ、デフォルトの Forms の動作を変更しないことです。