SAFETY-90: the peak guard goes on after a P1 meter gap

A meter gap past meter_max_age_s left seconds the quarter average never
counted, so the guard was blind for the rest of the quarter (rig case 7b:
3964.8 W against a 3450 W aim). Once readings are back, the missed seconds
now count at the higher of the limit and the import seen just before and
just after the gap with the batteries at 0 W (peakguard.gap_w/fill_gaps);
the gap's first meter_max_age_s is topped up to that too. Seconds before
the add-on's first reading count at the aim, and the page says part of the
period was not measured (EN/NL). The bill record is unchanged; no option.

DECISIONS/SAFETY-90-peak-guard-after-a-gap.md, test_safety90.py.

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

goodwe_controller/app/messages.py

@@ -793,6 +793,12 @@ def row_peak_guard_blind(why: str) -> str:
             f"meanwhile")
 
 
+def row_peak_guard_unmeasured() -> str:
+    """SAFETY-90. Before the first reading; that part counts as on target."""
+    return ("Peak guard: part of this 15-minute period was not measured, "
+            "counted as on target")
+
+
 def row_peak_guard_on(floor_w, limit_w, *, shadow: bool = False) -> str:
     if shadow:
         return (f"Peak guard: would ask for {watts(floor_w)} to stay under "
@@ -912,6 +918,7 @@ HINTS = {
     "peak_on": "Peak guard started",
     "peak_off": "Peak guard idle",
     "peak_blind": "Peak guard cannot read the meter well",
+    "peak_gap": "Meter is back, the peak guard counts the missed time as high use",
     "peak_saturated": T_PEAK_SATURATED,
     "peak_reserve": T_PEAK_RESERVE,
     "meter_frozen": T_METER_FROZEN,
@@ -1097,6 +1104,7 @@ def status_samples() -> list:
         ("row_peak_guard_idle", GREEN, row_peak_guard_idle(1300, 2500, True)),
         ("row_peak_guard_idle", GREEN, row_peak_guard_idle(1300, 2500, False)),
         ("row_peak_guard_quiet", GREEN, row_peak_guard_quiet()),
+        ("row_peak_guard_unmeasured", AMBER, row_peak_guard_unmeasured()),
         *(("row_peak_guard_blind", AMBER, row_peak_guard_blind(k))
           for k in BLIND_WORDS),
         ("row_peak_guard_on", AMBER, row_peak_guard_on(1200, 2500)),