[Bug] Agent tool worktree isolation fails with concurrent agents using stale commits

Bug Description

What happened

I fanned out four fix-agents, but the Agent tool's worktree isolation misbehaved: two agents forked from a stale commit (b177c45, 8 commits behind HEAD — before the table array-part work), and two silently committed onto
main. I detected this from contradictory agent reports, stopped, inspected the real git state, preserved everything as patches, and recovered the work cleanly rather than merging the tangle.

Environment Info

• Platform: linux
• Terminal: ghostty
• Version: 2.1.146
• Feedback ID: 0b19e760-ffe0-4b11-9d8e-c821ae60ed11

Errors

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