fix(power): exempt charge-limit oneshot from start rate limiting

Round 1 of #101's V3 failed on TuringMachine (2026-07-13 18:16): a
SPACED dock/AC event storm — each run finishing before the next event —
never coalesces, so 5 successful sub-second starts inside systemd's
default 10s window tripped start-limit-hit and marked the unit failed
(doctor badge) although every run succeeded. The write is idempotent
and cheap; rate limiting it only manufactures false failures, so the
unit sets StartLimitIntervalSec=0.

checks.battery-charge-limit now asserts the exemption and runs 8
sequential starts expecting a clean, non-failed state; the original
mid-run coalescing phase is unchanged.

Verified: V2 — the check passes under KVM (exit 0). V0 flake check
green. V3 round 2 re-queued in HARDWARE-QUEUE.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

agent/HARDWARE-QUEUE.md

@@ -11,20 +11,20 @@ the **T14s** (webcam case).
 
 ## Any machine (dev box is fine)
 
-- [ ] **#101 charge-limit service survives USB-C power-event bursts** —
-      after updating/rebuilding to the commit carrying this entry, clear the
-      old failure with `sudo systemctl reset-failed
-      nomarchy-battery-charge-limit.service`. Plug and unplug the powered
-      USB-C dock twice, allowing five seconds after the last transition.
-      **Pass:** `systemctl show nomarchy-battery-charge-limit.service -p
-      ActiveState -p Result` reports `ActiveState=inactive` and
-      `Result=success`; `systemctl is-failed
-      nomarchy-battery-charge-limit.service` is false; BAT0's
-      `charge_control_end_threshold` still matches the configured/live limit;
-      and `journalctl -b -u nomarchy-battery-charge-limit.service` contains
-      no new `SIGTERM`, `start-limit-hit`, or `Failed with result` lines after
-      the rebuild. Capture that journal plus `udevadm monitor
-      --subsystem-match=power_supply` if it fails.
+- [ ] **#101 charge-limit service survives USB-C power-event bursts**
+      (round 2) — round 1 FAILED on TuringMachine 2026-07-13 18:16: a
+      *spaced* storm (each run finished before the next AC event) landed 5
+      successful starts in 10s → `start-limit-hit`, unit marked failed,
+      doctor badge — although every run succeeded. Fixed by exempting the
+      unit from start rate limiting (`StartLimitIntervalSec=0`) + a
+      spaced-storm guard in `checks.battery-charge-limit` (the commit
+      carrying this entry). **Re-check:** after pulling/rebuilding this
+      commit, `sudo systemctl reset-failed nomarchy-battery-charge-limit
+      .service`, then plug/unplug the powered USB-C dock several times in
+      quick succession. **Pass:** `systemctl is-failed
+      nomarchy-battery-charge-limit.service` stays false, `Result=success`,
+      BAT0's `charge_control_end_threshold` still matches the limit, and the
+      journal has no new `start-limit-hit`/`Failed with result` lines.
 - [ ] **Docking recovery round 4 (#100, closed-lid BenQ sequence)** — after
       updating to the commit carrying this entry, run `nomarchy-home` and
       relogin. With the lid open, put visible windows on at least workspaces