Session and prompt lost when stopping an action or hitting the stop button

Bug Report

Description

When a user stops an in-progress action (e.g., hits the stop button during agent execution), the entire session — including the original prompt and any edits made to it — is deleted. This has happened multiple times.

Steps to Reproduce

1. Create a new session with a detailed prompt
2. The agent begins executing
3. Hit the "stop" button to cancel the action
4. The session disappears entirely — prompt, conversation history, and session are gone

Expected Behavior

Stopping an action should halt execution but preserve the session, the original prompt, and any conversation history up to that point. The user should be able to resume or re-run from that state.

Actual Behavior

The entire session is deleted, including the user's original prompt and any iterative edits they made to it. There is no way to recover the work.

Impact

• Loss of detailed, carefully crafted prompts that took time to write and iterate on
• User has to recreate the prompt from memory, losing edits made in the previous session
• Erodes trust in the tool for complex, multi-turn prompt development

Additional Context

• Reported by a user in the github/lifecyclemarketing project
• Has occurred multiple times (not a one-off)
• The lost session involved a complex weekly digest workflow prompt that had been edited several times before the stop action was triggered

編集した prompt でセッションを作成し、アクションを開始して停止ボタンを押すことで、問題を再現します。停止／キャンセルの経路を追跡して、セッションが削除される箇所を特定します。prompt、編集内容、会話履歴、セッションを再開または再実行できる状態で実行が停止すれば完了です。