chore(repo): Android-App als android/ ins Hauptrepo uebernehmen

Calendarr-Android wird mit vollstaendiger Historie als Unterverzeichnis
android/ eingebunden, damit Server, Web und die mobilen Apps in einem
Repo liegen.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

android/app/src/main/java/com/scarriffle/calendarr/MainActivity.kt

@@ -0,0 +1,26 @@
+package com.scarriffle.calendarr
+
+import android.os.Bundle
+import androidx.activity.ComponentActivity
+import androidx.activity.compose.setContent
+import androidx.activity.enableEdgeToEdge
+import androidx.core.splashscreen.SplashScreen.Companion.installSplashScreen
+import com.scarriffle.calendarr.ui.CalendarrRoot
+import dagger.hilt.android.AndroidEntryPoint
+
+@AndroidEntryPoint
+class MainActivity : ComponentActivity() {
+    override fun onCreate(savedInstanceState: Bundle?) {
+        // Covers the window from the first frame (incl. warm-start), then hands
+        // off to the in-app branded splash which stays until data is loaded.
+        installSplashScreen()
+        // Draw edge-to-edge so system-bar insets reach every window, including
+        // ModalBottomSheets — otherwise navigationBarsPadding() inside the sheets
+        // resolves to 0 and the bottom menu rows hide behind the nav bar.
+        enableEdgeToEdge()
+        super.onCreate(savedInstanceState)
+        setContent {
+            CalendarrRoot()
+        }
+    }
+}