SAFETY-81: no false 'Load too high' alarms

The alarm now also needs peakguard.load_too_high(): with the battery at
full power, the quarter still ends more than 10 W over the real limit.
The battery reading is the lower of this cycle's and the last, so a meter
sample from before the battery's last increase is not counted twice.
At most one alarm per quarter. Control outputs unchanged.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

goodwe_controller/DOCS.md

@@ -1739,7 +1739,8 @@ control action and goes to the action log and the status page. A *saturated*
 guard — asking for everything the inverter has while the quarter is still
 projected over — raises one notification (`goodwe_peak_saturated`), because that
 is the one state where the money will be spent and shedding load is the only
-thing left that changes the bill.
+thing left that changes the bill. SAFETY-81 keeps a 1 s meter spike, noise and
+a quarter's last seconds from raising it: see `peakguard.load_too_high()`.
 
 **And it sizes a price-driven charge, not only a forced discharge (SAFETY-45).**
 The same arithmetic read the other way answers *"how hard may this site charge
@@ -3211,9 +3212,11 @@ reason code `OUTPUT_CLAMP`.
 **Load too high for battery.** The capacity-peak guard (SAFETY-07) asks for
 everything the inverter can discharge and the running 15-minute average is
 still projected over the peak limit, so the month's billed peak
-(capaciteitstarief) goes up. In shadow mode the guard's projection is made on a
-plant that did not respond (SAFETY-47), and the text says so. See *The
-capacity-peak guard*.
+(capaciteitstarief) goes up. It fires only when, with the battery at full
+power, the period will still end more than 10 W over the real limit (not the
+margin's aim), and at most once per period (SAFETY-81). In shadow mode the
+guard's projection is made on a plant that did not respond (SAFETY-47), and
+the text says so. See *The capacity-peak guard*.
 
 **Battery stopped limiting the peak.** The peak guard may not discharge below
 `peak_soc_floor` (label “Peak reserve”, SAFETY-24). It also stops when the