Stale ids after replace/reload: orchestration tombstones, Codex window lease, PTY attach count across renderer reload #1283

Grouped P3s from the C2 hunt:

• OrchestrationBridge closed-child tombstones keep orchestrationParentId=P after the parent is reloaded as P'; P' list_agents/read_run_outputs omit the child and read_agent returns not-found.
• Codex same-rollout handoff: main kills the predecessor inside spawn and the renderer then skips killOwnedSession(oldId), the only release of SessionWindowRouter's lease for it; the old id stays owned for the app run.
• PTY attach counts are not tied to a webContents/document (unlike the perf(ipc): forward session:screen only to a renderer that leased it #1236 screen leases), so a renderer reload/crash leaves the count at 1; later detaches never reach 0, raw output keeps flowing to nobody, and the saved PTY size is never restored.

Found by the Stage 3 C2 hunt; lines are origin/main 9c6e48f. Findings file: temp/quality-loop/hunt-c2.md.

🤖 Generated with Claude Code