Show battery charge/drain rate ("9%/h") in details table and status notification (#108)

CONTEXT.md

@@ -0,0 +1,30 @@
+# Simple Battery Notifier
+
+An Android app that monitors the device battery and raises notifications for low/critical/full
+levels, high temperature, and battery health. This glossary pins down the terms the app's UI and
+code use so they don't drift.
+
+## Language
+
+**Drain rate**:
+How fast the battery level is falling while discharging, expressed in percentage-points per hour
+(%/h). The normalized, device-size-independent headline metric for consumption.
+_Avoid_: consumption, usage, speed.
+
+**Charge rate**:
+How fast the battery level is rising while charging, in %/h. The charging counterpart of the drain
+rate.
+_Avoid_: charging speed.
+
+**Instantaneous current**:
+The live current flowing in or out of the battery right now, in milliamps (mA), read from
+`BatteryManager.BATTERY_PROPERTY_CURRENT_NOW`. Shown as raw detail; not normalized, so it is not
+colored on its own.
+_Avoid_: amperage, draw, consumption.
+
+**Design capacity**:
+The battery's rated full capacity when new (mAh), from the manufacturer's spec. User-entered or
+best-effort auto-detected from the kernel. Distinct from the measured current full capacity.
+_Avoid_: rated capacity (in prose only), max capacity.
+</content>
+</invoke>

app/src/main/java/com/almothafar/simplebatterynotifier/model/BatteryDO.java

@@ -13,6 +13,9 @@ public final class BatteryDO {
 	private int voltage;
 	private boolean present;
 	private int capacity;
+	// Instantaneous current in µA from BATTERY_PROPERTY_CURRENT_NOW; Integer.MIN_VALUE when the device
+	// doesn't report it. Sign convention varies by OEM, so callers derive direction from the status.
+	private int currentMicroAmps = Integer.MIN_VALUE;
 	private String technology;
 	private String powerSource;
 	private String health;
@@ -124,6 +127,15 @@ public BatteryDO setCapacity(final int capacity) {
 		return this;
 	}
 
+	public int getCurrentMicroAmps() {
+		return currentMicroAmps;
+	}
+
+	public BatteryDO setCurrentMicroAmps(final int currentMicroAmps) {
+		this.currentMicroAmps = currentMicroAmps;
+		return this;
+	}
+
 	public String getPowerSource() {
 		return powerSource;
 	}

app/src/main/java/com/almothafar/simplebatterynotifier/receiver/BatteryLevelReceiver.java

@@ -10,6 +10,7 @@
 import com.almothafar.simplebatterynotifier.R;
 import com.almothafar.simplebatterynotifier.model.BatteryDO;
 import com.almothafar.simplebatterynotifier.service.BatteryHealthTracker;
+import com.almothafar.simplebatterynotifier.service.BatteryRateTracker;
 import com.almothafar.simplebatterynotifier.service.NotificationService;
 import com.almothafar.simplebatterynotifier.service.SystemService;
 import com.almothafar.simplebatterynotifier.util.TemperatureUtils;
@@ -64,8 +65,13 @@ public void onReceive(final Context context, final Intent intent) {
 		// Reuse the sticky intent we already read above instead of triggering a second read.
 		final BatteryDO batteryDO = SystemService.getBatteryInfo(context, batteryStatus);
 
-		// Keep the persistent foreground-service status notification live with the latest reading
-		NotificationService.updateOngoingNotification(context, batteryDO);
+		// Feed the charge/drain rate window from this broadcast (no polling timer of our own) so both the
+		// ongoing notification below and the details table reflect the latest reading (issue #108).
+		final BatteryRateTracker.BatteryRate rate = BatteryRateTracker.record(context, batteryDO);
+
+		// Keep the persistent foreground-service status notification live with the latest reading,
+		// reusing the rate just computed instead of re-parsing the persisted sample window.
+		NotificationService.updateOngoingNotification(context, batteryDO, rate);
 
 		if (batteryDO == null) {
 			// Without a real reading, don't assume a level. Previously this defaulted to 100%,