[Bug] Interrupted ExitPlanMode approval request falsely authorizes plan execution

Bug Description
Interrupting an ExitPlanMode approval request silently exits plan mode and tells the model it's authorized to act. Repro: in plan mode, Claude calls ExitPlanMode to request approval. User interrupts instead of approving. User sends any follow-up. Claude's retry of ExitPlanMode fails with "You are not in plan mode," and the harness emits: "## Exited Plan Mode — You have exited plan mode. You can now make edits, run tools, and take actions." Expected: an interrupted or errored approval request leaves plan mode on. Interrupting a request for approval is the opposite of granting it. Actual: plan mode is off and the model is affirmatively told it may now make edits, so it proceeds to implement an unapproved plan. The message asserts authorization that was never granted.

Environment Info

• Platform: darwin
• Terminal: Apple_Terminal
• Version: 2.1.195
• Feedback ID: 58492b2e-0b57-4898-b1da-0cbfb7eb2c9a

Errors

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