SAFETY-83: peak guard outranks the maintenance drain at N=1

At N=1 the drain is the site SET at P_MAINTENANCE (60), so the peak floor
(P_PEAK, 50) was not applied and the house imported what the drain left.
Where the floor asks for more than the drain rate, main.py now refiles the
peak claim at P_MAINTENANCE, so it wins; safety SETs still park everything.
Nothing else changes: safety78_identity --diff against 35cdffe changes only
cycles where the guard wanted more than the drain; N=2 is byte-identical.

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

goodwe_controller/app/arbiter.py

@@ -76,6 +76,10 @@ from . import allocator
 P_SAFETY = 100        # stopped, inputs missing, shutting down, device limits
 P_MAINTENANCE = 60    # maintenance owns the actuator outright (drain, hold)
 P_PEAK = 50           # capacity-tariff peak shaving - costs real money
+# The order in effect: safety limits and the SAFETY-73 refusal > the peak
+# guard > maintenance > modes > trade > loop. A peak floor above a drain still
+# binds: the `drain` site floor at N>=2 (SAFETY-78), refiled at P_MAINTENANCE
+# at N=1 (SAFETY-83). Not a maintenance HOLD at N=1 (DECISIONS/SAFETY-83).
 P_MAINT_SHAPE = 40    # maintenance shaping the loop (charge-only)
 # OPT-04. §10.1 priority 3 - price arbitrage. ⚠️ ITS POSITION IS THE SPEC, NOT A
 # preference: P_PEAK (50) is ABOVE it so clause 2 lets the capacity-tariff floor