Rebuild Noo as a full Nextcloud client: auth, media, and Material You UI

Replaces the starter template with Login Flow v2 auth, WebDAV-backed
Files/Photos/Activity tabs, a swipeable media viewer with PDF/text/video
preview, Material You dynamic theming, a frosted-glass floating nav bar,
and a rebranded app icon/identity (com.example -> family.nasa).

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

android/app/build.gradle.kts

@@ -5,7 +5,7 @@ plugins {
 }
 
 android {
-    namespace = "com.example.nextcloud_client"
+    namespace = "family.nasa.nextcloud_client"
     compileSdk = flutter.compileSdkVersion
     ndkVersion = flutter.ndkVersion
 
@@ -15,8 +15,7 @@ android {
     }
 
     defaultConfig {
-        // TODO: Specify your own unique Application ID (https://developer.android.com/studio/build/application-id.html).
-        applicationId = "com.example.nextcloud_client"
+        applicationId = "family.nasa.nextcloud_client"
         // You can update the following values to match your application needs.
         // For more information, see: https://flutter.dev/to/review-gradle-config.
         minSdk = flutter.minSdkVersion