feat: prioritize Bluetooth sensor data over GPS

- Restructured sensor logic to give absolute priority to Bluetooth sensors, largely ignoring GPS data for distance and speed calculations.
- Implemented downstream UI expansions, custom recording layouts, and new settings to reflect and control the new sensor-first flow.
- Added MediaNotificationListenerService and integrated media playback tracking within statistics.
- Modified VoiceAnnouncementUtils to harmonize announcements with the updated architecture.
- Added 'About This Fork' section to the README.

Note: These modifications were co-created with Antigravity AI.

src/main/java/de/dennisguse/opentracks/services/announcement/VoiceAnnouncementUtils.java

@@ -50,6 +50,21 @@ class VoiceAnnouncementUtils {
                 .append(context.getString(R.string.voiceIdle));
     }
 
+    static Spannable createLongBreak(Context context) {
+        return new SpannableStringBuilder()
+                .append(context.getString(R.string.voiceLongBreak));
+    }
+
+    static Spannable createSensorDisconnected(Context context) {
+        return new SpannableStringBuilder()
+                .append(context.getString(R.string.voiceSensorDisconnected));
+    }
+
+    static Spannable createSensorConnected(Context context) {
+        return new SpannableStringBuilder()
+                .append(context.getString(R.string.voiceSensorConnected));
+    }
+
     static Spannable createStatistics(Context context, Track track, SensorDataSet sensorDataSet, UnitSystem unitSystem, boolean isReportSpeed, @Nullable Statistics currentInterval, @Nullable SensorStatistics sensorStatistics) {
         Statistics trackStatistics = track.statistics();