fix(battery): Seed charge ETA from quick-charge specs, hide projection while charging

- While charging, the gauge showed the bare runtime projection when no charge
  rate existed yet — "1% · 4m" next to a charging chip reads as a four-minute
  charge. The line now shows the "until charged" ETA or nothing
- Seed the charge rate from Apple's published quick-charge claims ("5 minutes
  in the case provides around 1 hour of listening"), normalized against the
  rated listening hours, so the ETA is present from the very first charge; a
  live fit still takes over within minutes

app/src/test/java/eu/darken/capod/monitor/core/battery/BatteryEstimatorTest.kt

@@ -267,6 +267,16 @@ class BatteryEstimatorTest : BaseTest() {
         left.minutesUntilCharged shouldBe 28
     }
 
+    @Test
+    fun `the quick-charge rating seeds an ETA on the very first charge`() = runTest(UnconfinedTestDispatcher()) {
+        // Nothing measured, nothing stored — Apple's "5 minutes = ~1 hour of listening" claim
+        // (2.0/hr for a Pro 2) answers at once: 50% missing at 2.0/hr == 15 min.
+        val result = collectEstimate(
+            estimator(listOf(listOf(device("p1", left = 0.50f, right = 0.50f, charging = true, model = PodModel.AIRPODS_PRO2))))
+        )
+        result["p1"].shouldNotBeNull().left.shouldNotBeNull().minutesUntilCharged shouldBe 15
+    }
+
     @Test
     fun `a stored charge rate seeds time-until-charged immediately`() = runTest(UnconfinedTestDispatcher()) {
         // First charging emission, no live fit possible yet -> the persisted rate answers at once.

app/src/test/java/eu/darken/capod/pods/core/apple/ModelFeaturesTest.kt

@@ -155,6 +155,19 @@ class ModelFeaturesTest : BaseTest() {
         }
     }
 
+    @Test
+    fun `every battery spec carries a plausible quick-charge rate`() {
+        // Derived from Apple's published quick-charge claims; must sit inside the band the live
+        // fit is validated against, or the seed could never be corrected by a measurement.
+        PodModel.entries.forEach { model ->
+            val spec = model.batterySpec ?: return@forEach
+            withClue(model.name) {
+                val rate = spec.chargeFractionPerHour
+                (rate != null && rate in 0.25f..4.0f) shouldBe true
+            }
+        }
+    }
+
     private fun modelsWith(predicate: (PodModel.Features) -> Boolean): Set<PodModel> = PodModel.entries
         .filter { predicate(it.features) }
         .toSet()