Rename app to Castarr (dev.castarr.tv), add JDK toolchain resolution

Package/applicationId com.nodecast.tv -> dev.castarr.tv, all branding in app
and remote page renamed, remote localStorage key changed. Foojay toolchain
resolver + jvmToolchain(17) so hosts with only a JRE can build.

Closes #1

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

app/src/main/AndroidManifest.xml

@@ -15,7 +15,7 @@
         android:icon="@mipmap/ic_launcher"
         android:label="@string/app_name"
         android:usesCleartextTraffic="true"
-        android:theme="@style/Theme.NodeCast">
+        android:theme="@style/Theme.Castarr">
 
         <activity
             android:name=".MainActivity"