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/rescue-loose-home-scripts/SKILL.md

@@ -0,0 +1,44 @@
+---
+name: rescue-loose-home-scripts
+description: "Promote a durable loose $HOME script into dank/command-center: archive-first, black-box bats red-first with env seams, docs page + index + log entry, one atomic commit per instrument, PR to main."
+---
+
+Rescue a throwaway-looking `$HOME` script into the command-center repo as a maintained instrument. Used for `remote-job.sh` + `scripts/probes/*.hip` (PR #54, Refs #53); the archive still holds ~120 candidates.
+
+## 1. Archive first, never delete
+
+Loose scripts at `$HOME` root move to `~/.AGENTTRASH/home-scripts-<date>/` (`rm` is forbidden; deletion is a pruning session with Frank). Consolidate bulk media separately (`~/audiosamples`). Then check the archive for **instruments**, not convenience: something that answers a question you will ask again, or that carries a trap you paid for.
+
+## 2. Tests first, and black-box
+
+Write `tests/<name>.bats` before the script; confirm red (`bats tests/<name>.bats` → all `not ok` because the script is absent).
+
+- Assert **output, exit codes, and on-disk ordering** only — never internals, never "variable X equals Y".
+- A test that asserts a race outcome (file exists immediately after a detached `start`) is wrong: assert the *contract* instead (`status` reports RUN/PENDING and exits 1). Rewrite the test, not the code, when the failure is your own assumption.
+- Design env seams **so the untestable path becomes testable off the target hardware**: `*_SYSFS`, `*_KFD`, `*_HIPCC`, `*_SRC`, `*_BUILD`. A refusal that can only be exercised on a card box is an untested refusal. Stub the toolchain in `$PATH`/via env to drive build-failure and busy-device paths.
+
+## 3. Safety law in the tool, not the docs
+
+Anything that measures a GPU must **refuse before it builds or runs** when the device is busy (`gpu_busy_percent` over threshold, or any process holding `/dev/kfd`) and must **stop nothing**: unloading a production endpoint is a human decision (`--force`). Pin the refusal-before-build ordering in a test — otherwise a reordered guard silently reintroduces contention beside a live service.
+
+Exit-code taxonomy worth reusing: `0` did the work · `2` usage/missing inputs · `3` refused (would have contended) · `4` toolchain/build failure. A client box without the SDK must exit 4 loudly, never report an empty success.
+
+## 4. An instrument that crashes is not an instrument
+
+`hipGetDeviceProperties` **segfaults** on the fleet's ROCm build while `hipGetDeviceCount` works fine. The shipped probes called it only to print device name + PCI bus id — replaced by the sysfs topology block the driver prints (`current_link_width`/`current_link_speed` vs `max_*`). Record the trap as a comment in the sources so it is not reintroduced.
+
+## 5. Docs, three places, in the same commit as the code
+
+- `omp-docs/tools/<name>.md` — frontmatter per OKF (`type: reference`, title, description, tags, `verified`, `timestamp`); sections: contract (command table + exit status), the law + why, how to read the output, failure-modes table, test seams. Point-of-use only: measured numbers do **not** live here (they belong with the endpoint's runbook vault).
+- `omp-docs/tools/index.md` — one alphabetical bullet per page.
+- `omp-docs/log.md` — dated entry above the newest one: what changed + the durable laws, a few lines.
+
+Gates before commit: `bash scripts/kb-lint.sh` (0 violations) and full `bats tests/` green.
+
+## 6. Land it
+
+One commit per instrument (stage that page's index line only — re-add the next page's line for its own commit), message = imperative what + why + `Refs #N`, hooks armed (never `--no-verify`). Push to the local Gitea, open the PR with `gitea-pr-api-cycle` (token from `~/.config/secrets/gitea` via curl `-K`; body ends with `---` then `cwd: <session cwd> · session: <live transcript UUID>`), then `xdg-open <PR-URL>`. **Never merge without Frank's explicit OK.**
+
+## 7. Report the gap you could not close
+
+Verification on a client box proves the guard/refusal/usage paths only. If compile-or-run needs the hardware box, say so in the PR under "Not done here" and offer the exact low-risk command rather than implying the artifact is proven.