feat: Implement Spen integration for enhanced stylus support

TY Alexander!

app/src/main/AndroidManifest.xml

@@ -100,6 +100,12 @@
 			<intent-filter>
 				<action android:name="${applicationId}.action.READ_MANGA" />
 			</intent-filter>
+			<intent-filter>
+				<action android:name="com.samsung.android.support.REMOTE_ACTION" />
+			</intent-filter>
+			<meta-data
+				android:name="com.samsung.android.support.REMOTE_ACTION"
+				android:resource="@xml/remote_action"/>
 		</activity>
 		<activity
 			android:name="org.koitharu.kotatsu.search.ui.SearchActivity"

app/src/main/kotlin/org/koitharu/kotatsu/reader/ui/ReaderControlDelegate.kt

@@ -36,6 +36,17 @@ class ReaderControlDelegate(
 	}
 
 	fun onKeyDown(keyCode: Int): Boolean = when (keyCode) {
+
+		KeyEvent.KEYCODE_R -> {
+			listener.switchPageBy(1)
+			true
+		}
+
+		KeyEvent.KEYCODE_L -> {
+			listener.switchPageBy(-1)
+			true
+		}
+
 		KeyEvent.KEYCODE_VOLUME_UP -> if (settings.isReaderVolumeButtonsEnabled) {
 			listener.switchPageBy(-1)
 			true

app/src/main/res/xml/remote_action.xml

@@ -0,0 +1,19 @@
+<?xml version="1.0" encoding="utf-8"?>
+<remote-actions version="1.2">
+	<action
+		id="next_filter"
+		label="@string/prev_page"
+		priority="1"
+		trigger_key="L">
+		<preference name="gesture" value="swipe_left"/>
+	</action>
+
+	<action
+		id="prev_filter"
+		label="@string/next_page"
+		priority="2"
+		trigger_key="R">
+		<preference name="gesture" value="swipe_right"/>
+	</action>
+
+</remote-actions>