SAFETY-125: a grid charge counts a late meter reading's seconds; the guard row says "over" when it is

A meter reading late near a quarter's end left seconds the projection did
not count (SAFETY-99), and charge_headroom_w() read them as room: the cheap
run (and price trading, and the N=2 maintenance charge) went back to full
power in the quarter's last seconds and the quarter could land over a banked
month peak or the cap. peakguard.charge_room_w() counts those seconds at the
held reading for the charge only; the guard's floor is unchanged.

The guard row said "idle, heading for 5 814 W, under this month's 5 413 W
peak". Over the limit at the current rate the row and the month-peak line
now say so, and that the grid charge is cut back.

Version 0.19.2, CHANGELOG, DECISIONS. test_safety125.py new; the lag pins
in test_price_run_fixes.py and test_opt20.py and the AST pin in
test_arbitrage.py follow the change (see the pull request).

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

goodwe_controller/app/ui_text/en.json

@@ -416,6 +416,9 @@
     "step_in_would": "The batteries would step in above {kw}.",
     "period": "This 15-minute period is heading for {kw}.",
     "period_unmeasured": "Part of this 15-minute period was not measured.",
+    "period_over": "At this rate this 15-minute period reaches {kw}.",
+    "charge_cut": "The grid charge is cut back to stay under {kw}.",
+    "charge_cut_would": "The grid charge would be cut back to stay under {kw}.",
     "prices": {
       "now": "Price now {eur} per kWh, all in.",
       "today": "Today: lowest {lo} at {lo_at}, highest {hi} at {hi_at}.",