Day 1: wire dispatcher + sub-agent stubs + trace hook

[dadachi]

Summary

• Types in src/agents/types.ts model the domain spec, rename pairs, worker/reviewer/judge results, and the 6 AgentNames.
• Per-sub-agent trace hook in src/trace.ts appends timestamped lines to tmp/trace/<agent>.log — scripts/demo-tmux.sh panes light up during a run.
• 6 sub-agent stubs (planner, workers/{rails,ios,android}, reviewer, judge) emit realistic events and return mock results.
• Dispatcher (src/dispatch.ts) wires the pipeline: planner → Promise.all(rails, ios, android) → reviewer → judge. Parallel worker execution matches the demo beat-3 visual.
• CLI (src/index.ts) invokes dispatch(spec) and prints a summary when the run completes.
• Smoke test extended to cover the full dispatch pipeline end-to-end.

Closes Day-1 gate in docs-private/PLAN.md — "CLI dispatches; planner/workers/reviewer/judge files exist as typed stubs; per-sub-agent trace hook written; scripts/demo-tmux.sh lights up during a dry-run."

Test plan

• npm run ci — build + typecheck:tests + tests all pass (5/5, ~3.5s)
• npm run dev -- "a walk-in clinic queue..." — pipeline runs end-to-end, prints PASS, populates tmp/trace/{planner,rails,ios,android,reviewer,judge}.log with 3-5 events each
• Verified 2×2 tmux layout (scripts/demo-tmux.sh clinic-queue + tmux attach -t demo) shows events streaming into the four worker/reviewer panes during a run — confirmed via screenshot during rehearsal