Fix compressor metric comments: sensors_power_value is % of rated power

heating_compressors_0_sensors_power_value returns 0-100% of rated
compressor power, not watts. heating_compressors_0_power_value is the
constant rated power in kW (10 kW). Actual watts = sensors% × kW × 10.

Idle threshold of 20 remains correct: values are either 0% (idle) or
≥27% (running), so 20 cleanly separates them.

Grafana panel updated to show computed actual watts using the formula.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

configs/ems-config.yaml

@@ -10,7 +10,7 @@ prometheus:
     battery_soc: "ess_stateOfCharge_value"                     # 0-100%
     pv_production: "photovoltaic_production_current_value"     # watts
     battery_power: "ess_power_value"                           # watts
-    compressor_power: "heating_compressors_0_sensors_power_value"  # watts (actual power sensor; _power_value is a load level, not watts)
+    compressor_power: "heating_compressors_0_sensors_power_value"  # % of rated power (0=idle, 27-92=running); _power_value is rated kW (constant 10)
     ambient_temp: "heating_sensors_temperature_outside_value"  # °C
     phase_l1_power: "pcc_ac_active_power_phaseOne"             # per-phase grid power L1 (W)
     phase_l2_power: "pcc_ac_active_power_phaseTwo"             # per-phase grid power L2 (W)
@@ -78,7 +78,7 @@ strategic:
 
 # Consumer behavior — idle detection thresholds
 consumers:
-  compressor_idle_w: 20       # heat pump compressor below this = idle (W); sensors_power_value runs 27-80W when active, 0W when idle
+  compressor_idle_w: 20       # compressor idle threshold: sensors_power_value is % of rated power; 0%=idle, ≥27%=running → 20 cleanly separates them
   wallbox_min_charge_w: 50    # wallbox below this = car not charging (W)
   idle_cycles: 3              # consecutive idle cycles before early release (~6 min at 2-min poll)