Add delayed continuations and sleep circuit breaker

[firewalker06]

Summary

• add durable tycho agent send AGENT MESSAGE --delay SECONDS support with local/remote parity, exact due timestamps, due-aware FIFO batching, restart/concurrency safety, self-continuation ownership, and queue UI controls
• normalize Codex, Claude, and Pi pre-execution shell events at the stream-recorder boundary; stop the full harness process group on the third unique typed blocking wait
• persist a dedicated sleep_circuit_breaker outcome and one-shot, incident/generation-bound delayed recovery that manual intent cancels atomically
• capability-gate OpenCode after a live 1.18.4 probe exposed only a completed tool event
• update queue/delegation/Remote API/project docs and bundled Tycho skill guidance

Refs: Fizzy #225, Fizzy #227

Verification

• bin/test
• focused delayed-send CLI, queue, Remote API, scheduler, managed-agent, stream-recorder, UI, circuit-breaker, and recovery tests (all included in bin/test)
• isolated Chrome verification: exact delayed due time rendered; Edit/Delete remained available; breaker stop summary rendered as a distinct stopped conversation block
• live OpenCode 1.18.4 JSON stream probe for a real bash invocation

Residual risk

• OpenCode remains intentionally unsupported until it exposes a proven pending/running tool event.
• Due messages dispatch on the next existing server/scheduler/TUI poll rather than via a per-entry timer; they never dispatch early.