native: frame-rate setting, idle frame rate and battery power telemetry

- MtFrameRate setting (30 / 60 default / display max) as app.Get/SetFrameRateMode,
  with a "画面帧率" row injected into the system option dialog (mt_framerate); saved
  in the SDL pref path.
- FrameRatePolicy in the live loop: 30 fps after 15 s without input (not while auto
  hunting), display switched to 60 Hz unless the highest mode, ADPF
  setPreferPowerEfficiency, vsync pacing when the display already runs at the target.
  --fps-mode / --idle-fps / --idle-after; --fps-cap / --refresh-rate still pin a test run.
- Perf log: battery current/voltage/power, plugged, fps_mode, idle columns;
  perf_summary groups power by mode.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

android-native/app/src/main/java/org/metin2port/client/MainActivity.java

@@ -37,19 +37,20 @@ public class MainActivity extends SDLActivity {
         super.onCreate(savedInstanceState);
         setRequestedOrientation(ActivityInfo.SCREEN_ORIENTATION_SENSOR_LANDSCAPE);
         applyImmersiveMode();
-        chosenRefreshRate = applyRefreshRate(requestedRefreshRate(launchArgs()));
+        // --refresh-rate N pins the display mode for a test run; otherwise native_render switches it with
+        // the frame-rate setting (setDisplayRefreshRate).
+        final float pinned = requestedRefreshRate(launchArgs());
+        if (pinned > 0)
+            applyRefreshRate(pinned);
     }
 
-    // The display rate picked in onCreate (0: left to the system); handed to native as --refresh-rate.
-    private int chosenRefreshRate = 0;
-
     private String launchArgs() {
         Intent intent = getIntent();
         String args = intent != null ? intent.getStringExtra("args") : null;
         return args == null || args.trim().isEmpty() ? DEFAULT_ARGS : args;
     }
 
-    // --refresh-rate N (0 = system default); absent = the display's highest rate.
+    // --refresh-rate N (0 = system default); -1 when absent.
     private static float requestedRefreshRate(String args) {
         final String[] tokens = args.trim().split("\\s+");
         for (int i = 0; i + 1 < tokens.length; ++i) {
@@ -141,6 +142,52 @@ public class MainActivity extends SDLActivity {
         return tenths / 10f;
     }
 
+    // Called from native code (android_perf.h): the display mode whose refresh rate is closest to `hz`
+    // (the highest one when hz < 0), for the frame-rate setting. The panel then need not scan out at 120 Hz
+    // for a 60 fps game.
+    public void setDisplayRefreshRate(float hz) {
+        runOnUiThread(() -> applyRefreshRate(hz));
+    }
+
+    // Called from native code (android_perf.h): the highest refresh rate of the current resolution.
+    public float maxRefreshRate() {
+        final Display display = Build.VERSION.SDK_INT >= Build.VERSION_CODES.R ? getDisplay()
+            : getWindowManager().getDefaultDisplay();
+        if (display == null)
+            return -1f;
+        float best = display.getRefreshRate();
+        final Display.Mode current = display.getMode();
+        for (Display.Mode mode : display.getSupportedModes())
+            if (mode.getPhysicalWidth() == current.getPhysicalWidth() &&
+                mode.getPhysicalHeight() == current.getPhysicalHeight())
+                best = Math.max(best, mode.getRefreshRate());
+        return best;
+    }
+
+    // Called from native code (android_perf.h): BATTERY_PROPERTY_CURRENT_NOW as reported -- uA per the
+    // docs, mA on some vendors; the sign convention varies too (android_perf::battery_power sorts both
+    // out). 0 if unknown.
+    public float batteryCurrentRaw() {
+        final BatteryManager manager = (BatteryManager) getSystemService(BATTERY_SERVICE);
+        if (manager == null)
+            return 0f;
+        final int raw = manager.getIntProperty(BatteryManager.BATTERY_PROPERTY_CURRENT_NOW);
+        return raw == Integer.MIN_VALUE ? 0f : raw;
+    }
+
+    // Called from native code (android_perf.h): battery voltage in mV, -1 if unknown.
+    public float batteryVoltage() {
+        final Intent battery = registerReceiver(null, new IntentFilter(Intent.ACTION_BATTERY_CHANGED));
+        return battery != null ? battery.getIntExtra(BatteryManager.EXTRA_VOLTAGE, -1) : -1f;
+    }
+
+    // Called from native code (android_perf.h): 1 while a charger is connected (the current then no
+    // longer measures the game's draw), 0 otherwise.
+    public float batteryPlugged() {
+        final Intent battery = registerReceiver(null, new IntentFilter(Intent.ACTION_BATTERY_CHANGED));
+        return battery != null && battery.getIntExtra(BatteryManager.EXTRA_PLUGGED, 0) != 0 ? 1f : 0f;
+    }
+
     // Called from native code (android_perf.h): the rate the display runs at now.
     public float currentRefreshRate() {
         final Display display = Build.VERSION.SDK_INT >= Build.VERSION_CODES.R ? getDisplay()
@@ -204,8 +251,6 @@ public class MainActivity extends SDLActivity {
         // Test phase: FPS readout in the top-left corner. Drop this line for release builds.
         if (!args.contains("--show-fps"))
             args = args.trim() + " --show-fps";
-        if (!args.contains("--refresh-rate") && chosenRefreshRate > 0)
-            args = args.trim() + " --refresh-rate " + chosenRefreshRate;
         return args.trim().split("\\s+");
     }