Add agent-agnostic peer discovery and durable task communication

[parsakhaz]

Pane already has a local socket daemon, but an idle terminal cannot identify which dispatched task was consumed or completed. This adds a common task protocol while preserving the existing terminal and worktree orchestration.

• Add durable, addressed messages in sessions.db with stable request IDs, atomic inbox claims, immutable terminal replies and revision-based waits.
• Add the same peers discovery/send/inbox/reply/wait commands to npm and Python CLIs. Managed guidance and environment hints expose them to arbitrary agent runtimes.
• Bundle an optional Pi extension using native message delivery. It never treats turn_end or agent_settled as task completion and never automatically replays an uncertain claim.
• Add watch --quiet-panel for correlated work, retaining blockers, held input and exits. Terminal wakes remain explicit, guarded and unconfirmed until a receipt.
• Document recovery, capability limits, the Pi source investigation and an 18-scenario token simulation using the shipping watcher cadence.

For two false-ready pauses per task, simulated savings range from 3.0% to 62.3%, depending on extra receiver model turns. Clean readiness can make added messaging more expensive. These are synthetic coordination estimates, not measured billing.

Verified on dec7ea2: all 13 checks passed, including six npm/Python wrapper configurations across Linux/macOS/Windows, main-process suites on all three systems, consolidated lint, workspace types, the main/Pi bundle build, frontend tests and Electron/functional smoke tests. CI evidence.

Both automated review findings were fixed and resolved: terminal wakes now claim the requested message id, and quiet readiness still cancels pending blockers before output is suppressed. Targeted regression tests cover both. The wrapper fixture also handles expected client-disconnect races exposed by macOS CI.

A live authenticated Pi model session was not exercised; the adapter is verified against the pinned upstream API contract and automated delivery/recovery lifecycle tests. The documentation states this integration limit.

Canonical Codex/Claude orchestrator guidance: https://github.com/dcouple/skills/pull/94

Closes #638.

[chatgpt-codex-connector]

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Review	Status	Commit	Review trigger
📝 Code Review	✅ Completed 2026-09-14T11:22:09.041408Z	08986b0	PR opened

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Reviewed commit: 08986b0894

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