Remote server: idle sessions cannot be resumed from mobile/web UI but can from CLI

Description

When using the Claude Code remote control server, idle sessions cannot be resumed from the mobile app (and presumably the web UI, which is assumed to use the same mechanism). However, the same idle sessions can be resumed without issue from the CLI.

Behavior

• Starting new sessions: Works fine from the mobile app via the remote server
• Resuming idle sessions (after a few hours of inactivity): Fails from the mobile app — the UI keeps spinning indefinitely
• Resuming idle sessions from CLI: Works fine against the same remote server and same session

Steps to Reproduce

1. Start a Claude Code remote control server on a machine
2. Connect from the Claude Code mobile app and start a conversation
3. Leave the session idle for a few hours
4. Attempt to resume the session from the mobile app
5. Observe: UI spins indefinitely, session cannot be resumed
6. Attempt to resume the same session from the CLI
7. Observe: resumes successfully

Expected Behavior

Idle sessions should be resumable from the mobile app the same way they are from the CLI.

Hypothesis

The mobile app (and possibly web UI) may be reusing a stale websocket connection or session token that expires during the idle period. The CLI likely authenticates fresh on each invocation and does not hit this expiry. The remote server may also be dropping idle websocket connections in a way the mobile client does not recover from gracefully.

Environment

• Remote control server running on Linux
• Client: Claude Code mobile app
• CLI resume works correctly against the same server