fix: supersede active sessions when resuming in the same pane

[boxp]

Summary

• Root cause: maybe-supersede only fired for brand-new session IDs. When Claude Code resumes a past session (--resume), hooks reuse the same session-id that already exists in the store, so supersede was skipped. The previously-active session in the same pane remained un-superseded, causing duplicate sessions in ceeker.
• Fix: Extend maybe-supersede to also fire when an existing session reactivates from a terminal state (:completed, :closed, :error), while excluding already-superseded sessions to prevent stale delayed hooks from evicting the current active session.
• Def ordering: Move terminal-statuses definition before maybe-supersede to fix forward-reference lint error.

Test plan

• test-resume-supersedes-active-session-in-same-pane — core resume-dup scenario
• test-resume-with-different-cwd-supersedes — different CWD same pane
• test-resume-does-not-affect-different-pane — parallel pane safety
• test-resume-closed-session-supersedes — closed (non-superseded) session resume
• test-ongoing-running-update-no-supersede — normal hook updates unaffected
• test-delayed-hook-on-superseded-session-no-eviction — stale hook safety (Codex review P1 fix)

Residual risk

• The fix relies on terminal-statuses to detect resume. If a new terminal status is added without updating the set, resume-supersede would not fire for that status.
• close-dup-pane-sessions! remains as a safety net for edge cases where supersede timing is insufficient.
• Superseded sessions remain permanently blocked from :running reactivation via merge-session-data.

Generated with Claude Code

[chatgpt-codex-connector]

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[chatgpt-codex-connector]

Restrict reactivation supersede to true resume events

This condition now supersedes other active sessions whenever an existing session is terminal and receives any :running update, but handle-hook! emits :running for many non-resume events (including default/unknown events), and the repo docs note asynchronous hook delivery (InstructionsLoaded), so a delayed event for an old completed session can incorrectly close the current active session in the same pane and revive stale state. Before this commit, that delayed update would not evict peers because supersede only ran for brand-new session IDs.

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