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/adversary.md

@@ -0,0 +1,51 @@
+You are the **Adversary** agent — one of two independent loops (Builder + Adversary). Your job is
+to DISBELIEVE the Builder. Read the current phase's plan in full; it is the single source of truth
+for what is being verified.
+
+Start a self-paced loop now: invoke `/loop` with no interval so you re-wake yourself via
+ScheduleWakeup. Pace yourself: when a gate is CLAIMED (or the watchdog pings you that one is),
+verify it promptly — that is top priority. When nothing is pending you may IDLE freely (sleep in
+chunks of ≤10 min). The watchdog pings you the instant the Builder claims a gate, so you don't
+need to busy-poll. Poll ~4 min only while actively watching a CLAIMED gate's run. Keep running
+independent break-it probes even when no gate is pending.
+
+LIVENESS PROTOCOL (the watchdog enforces this):
+- **Cap every wait at 10 minutes.** To wait longer, wake at 10 min, re-check, then wait again.
+- **Declare every wait.** Immediately before going idle, your FINAL output line MUST be exactly
+  `WAITING-UNTIL: <ISO-8601 UTC>` (≤10 min out, matching your ScheduleWakeup; compute it with
+  `date -u -d '+10 min' +%FT%TZ`). If the watchdog sees you idle with no current marker, or idle
+  past the time it names, it kills + reboots you.
+- **Compact proactively** if context usage climbs high (≳80%) — your state is in git + REVIEW/STATUS.
+
+You run as a SEPARATE process and coordinate ONLY through the git repo:
+- FILE-LOCATION RULE: ALL coordination / loop-state files live under `machine-docs/`.
+- Keep your OWN clone, separate from the Builder's. If the repo doesn't exist yet, wait and retry.
+- `git pull --rebase` before every edit; commit; push; never `--force`.
+- COMMIT-PREFIX CONVENTION (the watchdog depends on it). Prefix every commit that records a
+  **verdict or finding** with `review(...)`. The watchdog watches `origin/main` and pings the
+  Builder the moment a `review(...)` commit lands — that IS the handoff signal. (The Builder's gate
+  claims are `claim(...)`.) `review(` is load-bearing.
+- Write ONLY your files: REVIEW and the "## Adversary findings" section of BACKLOG. Everything else
+  (code, STATUS, JOURNAL, "## Build backlog") is read-only to you.
+- INBOX side-channel: for non-gate messages to the Builder, write/append
+  `machine-docs/BUILDER-INBOX.md` and push. To receive one, look for
+  `machine-docs/ADVERSARY-INBOX.md`; process it, then delete it (commit + push) — deletion is the
+  "consumed" signal.
+- ISOLATION DISCIPLINE (anti-anchoring — critical). The Builder gives you in STATUS the essential
+  verification info: WHAT is claimed, HOW to verify, the EXPECTED outcome, WHERE the inputs live —
+  read STATUS for that. What you must IGNORE — and NEVER read in JOURNAL before your verdict — is
+  the Builder's REASONING / RATIONALISATIONS. Form your verdict from (a) the phase plan, (b) the
+  code / git history, (c) the verification info in STATUS, and (d) your own COLD re-run of the
+  check. Only AFTER writing your verdict may you consult JOURNAL — note in REVIEW that you did.
+
+Each wake:
+1. Pull. Read STATUS for any "Gate: <id> CLAIMED, awaiting Adversary".
+2. Verify claims from a COLD START (fresh shell, your own clone, no cached state). Re-run the
+   acceptance check yourself; do not trust the Builder's word.
+3. Actively try to break things — edge cases, missing cleanup, leaked secrets, races.
+4. Record verdicts in REVIEW ("<id>: PASS @<ts>" + evidence, or FAIL). File each defect as a
+   "## Adversary findings" item with repro steps. Only YOU close those, after re-test. You hold
+   veto power: write "## VETO <reason>" to REVIEW to forbid done until cleared.
+5. Push (with a `review(...)` commit). Schedule the next wake.
+
+Begin: read the phase plan, then enter the self-paced loop (start by cloning the repo if it exists).