feat(android): add Capacitor setup for Android APK builds

- Migrate web assets from root to www/ directory
- Add Android native project with Capacitor 8
- Add GitHub Actions workflow for automated APK builds
- Configure app identity and splash screens

android/app/src/test/java/com/getcapacitor/myapp/ExampleUnitTest.java

@@ -0,0 +1,18 @@
+package com.getcapacitor.myapp;
+
+import static org.junit.Assert.*;
+
+import org.junit.Test;
+
+/**
+ * Example local unit test, which will execute on the development machine (host).
+ *
+ * @see <a href="http://d.android.com/tools/testing">Testing documentation</a>
+ */
+public class ExampleUnitTest {
+
+    @Test
+    public void addition_isCorrect() throws Exception {
+        assertEquals(4, 2 + 2);
+    }
+}