chore(agent): commit the machine tier and the doctrine text the checkout was already running

Landing blocker for #61 and #63: the deployment checkout is 12 commits behind and
`merge --ff-only` refuses while tracked paths are dirty. Discard is not available here
(workspace policy: no `checkout`/`stash` on shared state), so the dirt is committed.

- `agent/APPEND_SYSTEM.md`: the point-of-use / one-work-log / PR-link doctrine, already
  byte-identical to `origin/main` (`cmp` against the trunk blob: no difference). No new
  prose — the commit exists so the trunk merge can proceed.
- `agent/config.yml` and `agent/managed-skills/**`: the machine-live tier the heartbeat
  owns (AGENTS.md § Live-sync tiers).

`ALLOW_SECRETS=1` was used, deliberately and after auditing the staged diff by hand: the
only credential-shaped strings in it are two copies of `AKIA0000000000000EXAMPLE` — the
inert all-zero AWS example id — and they appear inside the two skill pages that teach
that exact placeholder shape. This checkout is still running the pre-#61 hook; the merged
gate (value-scoped placeholder filter, `71601f7`) exempts this value, so the refusal
dies with this landing. No `--no-verify` was used: the gate ran and its verdict is
recorded here.

Refs #61

agent/managed-skills/omp-background-job-deadline-debug/SKILL.md

@@ -0,0 +1,41 @@
+---
+name: omp-background-job-deadline-debug
+description: "Diagnose a background bash job/service killed mid-run (\"Command timed out after Ns\") in omp: find which deadline owned it (tools.maxTimeout cap vs async default), prove it from the bundle, and launch long jobs uncapped as ready-log services."
+---
+
+# Omp background-job deadline forensics
+
+Symptom: an async `bats`/build job dies with `[Command timed out after 300s|600s]`
+while the same launch once ran 18+ min ("no deadline").
+
+## Cause map (proven against the pinned bundle)
+Resolver in `dist/cli.js`: `let v=n??300, R=v===0, k=R?void 0:ep("bash",v,x)` where
+`qx.bash={default:300,min:1,max:3600}` and `x` = config key `tools.maxTimeout`
+("Maximum timeout in seconds the agent can set for any tool", default 0).
+- Request absent → `qx.bash.default` 300 s.
+- Request > 0 → clamped by `tools.maxTimeout` when set (e.g. 600 caps a 1800 request).
+- Request 0 → meant "no deadline", but `0` sometimes arrives as missing (falsy drop
+  upstream of the resolver) → silently 300 s. Filed as tool issue; treat any
+  async job over ~5 min as untrustworthy.
+
+## Diagnose in three moves
+1. `grep -o 'qx={bash:{[^}]*}' <omp bundle>` — policy table (`command -v omp` →
+   `readlink -f` → `dist/cli.js`).
+2. `read cfg://tools` — live `maxTimeout` (value ≠ 0 explains any hard cap).
+3. Compare kill notices: the number in "killed once it has run Ns" is the resolved
+   deadline; 300 = default reached (request dropped), other values = your request
+   or the config cap.
+
+## Launching jobs longer than the cap
+- Named **services are not deadline-capped**: `bash(name:"x", pty:false, command:"…; echo DONE >> log", ready:{log:"DONE", timeout:900})`.
+  Readiness fires on the log pattern; result does NOT auto-deliver — `wait` on it or read `proc://x` after the supervisor notice.
+- NEVER end the service command with `echo "EXIT $?" >> log` and trust the
+  supervisor's exit code — the trailing echo masks it (supervisor reports 0 while
+  the log says EXIT 1). The log line is the truth; grep the log for the recorded
+  code and `^not ok` before believing any "exit code 0".
+- Do not raise `tools.maxTimeout` unasked: session-scoped `write cfg://tools/maxTimeout`
+  needs user approval and may be declined — respect it, use the service route.
+
+## Multi-suite hazard
+Suites that rebuild shared artifacts per test (e.g. dankvoice bats rebuilds `dist/`)
+must not run concurrently — one suite at a time, or per-worktree copies only.