feat: agent-orchestrator v0.1.0 — generic multi-agent harness

Extracted and generalized from a project-specific agent launch engine. No project
specifics remain in code: paths, the loop kickoff preamble, handoff conventions, and the
on-complete hook are all config/template driven; session_prefix + log_dir are required.

- agents.py: driver + watchdog (data-driven backends via prompt_delivery arg|ping|exec;
  required session_prefix/log_dir; project-rooted path resolution; configurable kickoff
  template, handoff patterns, on_complete task; tmux-safe; selftest + init verbs)
- agent-log.py: config-driven claude transcript renderer
- agents.example.toml: self-contained 2-agent example (dependency-free demo backend)
- prompts/: generic builder/adversary/kickoff templates
- smoke.sh: isolated up+down sandbox proof that cleans up after itself
- flake.nix/.lock: devShell (python311 + tmux + git)
- README.md: schema + verbs + AI-PO usage + nix

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

prompts/kickoff.md

@@ -0,0 +1,19 @@
+*** PROJECT PHASE: {phase_id} ***
+SINGLE SOURCE OF TRUTH for THIS phase: {plan} — read it in full now; it defines this phase's
+mission and Definition of Done.
+
+Track loop state in PHASE-NAMESPACED files UNDER `machine-docs/` in your repo clone (create the
+dir if missing): `machine-docs/{status}`, `machine-docs/BACKLOG-{phase_id}.md`,
+`machine-docs/REVIEW-{phase_id}.md`, `machine-docs/JOURNAL-{phase_id}.md`. `machine-docs/DECISIONS.md`
+is shared (append-only, joint authority).
+
+FILE-LOCATION RULE (mandatory): ALL coordination / loop-state files live under `machine-docs/`,
+NEVER the repo root — that includes STATUS/BACKLOG/REVIEW/JOURNAL (phase-namespaced),
+DECISIONS.md, and the ADVERSARY-INBOX.md / BUILDER-INBOX.md side-channels. If you find one at the
+root, `git mv` it into `machine-docs/`.
+
+"Done" for this phase = the Builder writes the done marker ("## DONE") to `machine-docs/{status}`
+ONLY after every Definition-of-Done item is Adversary-verified with a fresh PASS in
+`machine-docs/REVIEW-{phase_id}.md`.
+
+=== standing role & rules ===