phase: 12_nut_self_test_verdict

Final state verified. Report:

**Verified (phase 12 — all 3 tasks already complete; this was the verification pass)**
- Re-ran the wire capture live: `ups.test.result` = `No test initiated` (apc) / `Done and passed` (cyberpower) — matches `LIVE_SELF_TEST_WORDS` + both fixtures; `/api/summary` has **no** self-test row, `/api/ups/snapshot` reads `cyberpower ok | Done and passed`, `apc unknown | …run a battery test`; both screenshots read back correct.
- Fixed a defect found in prior work while checking the "unrelated live noise" note: `NutMonitor.collect()` reused one upsd socket after a *partially-read* reply, so a 4 s stall produced bogus `expected 'BEGIN LIST VAR', got 'RW apc battery.charge.low "10"'` errors (same hazard on `INSTCMD`, where a late `OK` could be read as a different command's success). `NutClient` now marks a socket whose reply stopped early as `UNUSABLE`, naming the command that stalled; a complete `ERR …` line still leaves it usable (the per-UPS tolerance `collect()` depends on). +3 hermetic pins against the fake upsd; live re-check (09:33–09:44) now logs one line per stall, no cascade.

**Tests / lint / coverage (all green)**
- `bash .agents/validate.sh` → **exit 0**; `uv run pytest --cov --cov-fail-under=94` → **1172 passed, 11 skipped**, coverage **98.63 %** (floor 94); `uv run ruff check src tests agent` clean; `uv run pyright` 0 errors; `node --check` clean. Modified modules: `sources/nut.py` 95 %, `collectors.py` 97 % (no new line uncovered).
- `uv run pytest -m live --live` → **8 passed / 3 failed**, all three the pre-existing `driveripper` agent-transport failures AGENTS.md records (verified still true: unit `inactive`, no installed file, nothing on `:9120`).
- `./scripts/dev-server.sh status`: `nut ok`, `llm:* ok`, `host/disks:deskwork|gateway ok`; the two `driveripper` jobs DOWN.

**Completion criteria**
- Live capture recorded + asserts `ok` — met (re-confirmed from the wire today).
- `/ups` renders `ok`, overview silent, screenshots present — met.
- pytest / cov / ruff / pyright / validate — met (above).
- No other `health.checks[]` behaviour changed — met (diff confined to the `test_result` branch; all prior nut/ups-contract tests unmodified).

**Documentation**: README verified consistent (self-test wording, config table cross-checked against `config.py`, all documented commands/flags exist) — no changes needed beyond phase tasks' edit. AGENTS.md fixes: stale test count (1140 → 1172), `nvme0n1` power-on hours 19 158 → 19 160, gap 4 store-error claim corrected (last stored `store-error` 2026-10-18 06:33, none in the previous 24 h), new `collectors.py`/`sources/nut.py` socket-hygiene note, new gap-1 bullet on the upsd stall, plus live evidence appended to `data/logs/NOTES-self-test.md`.

**Deviations**: made no live *changes* (read-only probes only) — `driveripper`'s agent install needs root (`ops` has no installer/visudo grant) and a battery test stays the operator's call; the upsd 4 s stall itself is upstream-side. `uv pip list --outdated` still advisory (certifi/fastapi/starlette) — dependencies untouched this phase.

**Next pending phase**: `13_llm_page_and_decode_rate`.

tests/fixtures/nut_apc.vars

@@ -9,7 +9,7 @@ VAR apc battery.charge.low "10"
 VAR apc battery.charge.warning "50"
 VAR apc battery.date "2001/09/25"
 VAR apc battery.mfr.date "2021/06/24"
-VAR apc battery.runtime "633"
+VAR apc battery.runtime "621"
 VAR apc battery.runtime.low "120"
 VAR apc battery.type "PbAc"
 VAR apc battery.voltage "27.3"
@@ -36,13 +36,13 @@ VAR apc driver.version.usb "libusb-1.0.30 (API: 0x0100010C)"
 VAR apc input.sensitivity "medium"
 VAR apc input.transfer.high "144"
 VAR apc input.transfer.low "88"
-VAR apc input.voltage "123.0"
+VAR apc input.voltage "124.0"
 VAR apc input.voltage.nominal "120"
-VAR apc ups.beeper.status "disabled"
+VAR apc ups.beeper.status "enabled"
 VAR apc ups.delay.shutdown "20"
 VAR apc ups.firmware "952.e5 .D"
 VAR apc ups.firmware.aux "e5     "
-VAR apc ups.load "50"
+VAR apc ups.load "46"
 VAR apc ups.mfr "American Power Conversion"
 VAR apc ups.mfr.date "2021/01/08"
 VAR apc ups.model "Back-UPS RS 1500MS"