Anti-conflict guard: hysteresis + per-cycle decision log

[partach]

Customer reported visible flipper behaviour during long discharge windows: discharge → idle → discharge every ~16 seconds. Logs showed the anti-conflict guard tripping on momentary grid imports as small as 281W (just over the 200W threshold). Each flip is two Modbus writes and a physical inverter mode switch — rough on hardware and customers notice the on/off cycling.

The 200W threshold is easily crossed by everyday loads: kettle, oven preheat, EV charging start, even a fridge compressor kick. When the battery is exporting to the grid and load briefly spikes above the inverter discharge power, the meter reads a few hundred W of import for one polling cycle.

Hysteresis added:

• Small/moderate import (200-2000W) must persist for ≥ 2 consecutive cycles (~32s) before suppression triggers.
• Large import (> 2000W) suppresses immediately (genuine sustained draw like EV charging or oven preheat).
• After suppression ends, a 60s cooldown blocks re-suppression so the inverter stabilises before the next decision.

Diagnostic logging:

• Each tick now logs the full state decision at DEBUG level: desired/current state, SOC, price, threshold, grid_power. Makes flipper investigations straightforward — the customer log pattern would have stood out in seconds with this in place.
• Anti-conflict ramp-up (tick N of M) logs at DEBUG; suppression trigger stays at INFO with the sustained/large reason.