v1.0.21-beta.4

Added

• Additional solar source for AC-coupled installs (cloud mode). New optional config additional_pv_power_variable (e.g. meterPower2) names a FoxESS telemetry variable whose value is added to pvPower, so the control algorithm sees true total generation when a second inverter's output is reported in a separate variable rather than the FoxESS pvPower reading. REST-polled and held across WebSocket frames; raw additive; off by default (blank). A persistently-missing configured variable is surfaced as a diagnostics error (C-020/C-026). As a side benefit, feeding the external term into pvPower improves the WS grid-direction inference that previously diverged on unmeasured external generation.