docs(telemetry): cite where the usable capacity figure comes from

61,7 kWh usable against a 64 kWh nameplate is EVKX's specification sheet for
the MG4 Long Range, not a measurement of any particular pack. Saying so in
the class that consumes it keeps the distinction visible at the point where
someone would otherwise be tempted to treat a spec figure as a reading.

The workspace AGENTS.md carries the rule this follows.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

Author: malys

lib/src/main/java/com/evsuite/hardware/telemetry/BatteryCapacityConfig.kt

@@ -10,10 +10,15 @@ package com.evsuite.hardware.telemetry
  * for exactly what it is.
  *
  * **Usable, not nameplate.** State of charge spans the usable window, not the gross pack: the
- * buffers at each end are outside it. An MG4 sold as a 64 kWh car does not put 64 kWh between
- * 0 % and 100 %, and using the nameplate figure would overstate every arrival forecast by the
- * size of those buffers, in the optimistic direction. The field asks for the usable figure and
- * nothing here converts one into the other, because the relationship is not published either.
+ * buffers at each end are outside it. The MG4 Long Range is sold as a 64 kWh car and its usable
+ * capacity is 61,7 kWh — EVKX's specification sheet for that model, reviewed 2026-09-04, and a
+ * citation rather than a measurement of any particular pack. Entering the nameplate figure
+ * would overstate every arrival forecast by the size of those buffers, in the optimistic
+ * direction. The field asks for the usable figure and nothing here converts one into the other:
+ * the relationship is model-specific and this layer serves more than one model.
+ *
+ * See the workspace `AGENTS.md` for how a specification sheet may be used — it corroborates a
+ * declared figure and never stands in for on-vehicle evidence.
  *
  * **Everything derived from this is [Provenance.ESTIMATED].** A dealer's state-of-health
  * reading is itself an estimate, the usable figure is a specification rather than a

lib/src/test/java/com/evsuite/hardware/telemetry/BatteryCapacityConfigTest.kt

@@ -8,7 +8,10 @@ import org.junit.Test
 
 class BatteryCapacityConfigTest {
 
-    /** The reported MG4: 64 kWh nameplate, about 61.7 kWh usable, 95 % state of health. */
+    /**
+     * The owner's MG4 Long Range: 64 kWh gross and 61,7 kWh usable per EVKX's specification
+     * sheet, at the 95 % state of health the dealer reported.
+     */
     private val mg4 = BatteryCapacityConfig.of(61.7, 95.0)!!
 
     @Test fun `state of health scales the usable pack`() {