[BUG] [Routines] Scheduled run stuck in "En cours d'exécution" for 2+ days (zombie execution)

Preflight Checklist

• [x] I have searched existing issues and this hasn't been reported yet
• [x] This is a single bug report (please file separate reports for different bugs)
• [x] I am using the latest version of Claude Code

What's Wrong?

<img width="1433" height="1063" alt="Image" src="https://github.com/user-attachments/assets/672bd745-98c4-4b24-8012-8baf189ea6e2" />

Bug report

A scheduled Routine run has been stuck in "En cours d'exécution" (running) state
since April 18, 2026 at 14:05 UTC+2. It never completed or timed out.

Steps to reproduce

1. Create a daily Routine running at 14:00 UTC+2
2. Observe the April 18 execution — it never terminated
3. The run still shows "En cours d'exécution" 2 days later

Expected behavior

The run should either complete (success/failure) or timeout after a reasonable duration.

Actual behavior

The execution is permanently stuck in "running" state with no way to cancel it from the UI.
Subsequent runs (April 19, April 20) completed successfully, so the zombie run does not
block new executions, but it may consume usage quota.

Environment

• Platform: Claude.ai web (Routines)
• Run type: Programmé (scheduled)
• Routine: remote ("À distance")

What Should Happen?

The scheduled Routine run should complete (success or failure) within a
reasonable time, or timeout automatically. A cancel/stop button should be
available in the UI to terminate a stuck run manually.

Error Messages/Logs

No error message visible. The run shows "En cours d'exécution" (running) 
indefinitely with no output, no error, and no cancel button in the 
Routines execution history panel.

Steps to Reproduce

1. Create a daily scheduled Routine on claude.ai web (Routines feature)
2. Let it run — if the execution hangs, it enters an infinite "running" state
3. Navigate to Routines → execution history
4. Observe: the stuck run shows "En cours d'exécution" with no cancel button
5. Subsequent scheduled runs complete successfully, but the zombie run

remains stuck indefinitely (confirmed: 2+ days stuck)

Note: closest related issue is #40534 (different feature, same hang pattern)

Claude Model

Opus

Is this a regression?

I don't know

Last Working Version

_No response_

Claude Code Version

1.3561.0 (fbc74b)

Platform

Other

Operating System

macOS

Terminal/Shell

Other

Additional Information

Claude Desktop