fix: replace download flow with manual transfer instructions; rename app package

The Gemma model requires Kaggle login/licence so direct HTTP download is
not possible. Replaces the download screen with adb transfer instructions,
a Scan button that checks the file on disk, and a Continue without AI bypass.

Also renames the Android package from com.example.dailyou to
net.stefwill.dailyou (build.gradle.kts, MainActivity.kt path + declaration)
and adds *.bin to .gitignore to keep model files out of the repo.

android/app/build.gradle.kts

@@ -6,7 +6,7 @@ plugins {
 }
 
 android {
-    namespace = "com.example.dailyou"
+    namespace = "net.stefwill.dailyou"
     compileSdk = flutter.compileSdkVersion
     ndkVersion = flutter.ndkVersion
 
@@ -22,7 +22,7 @@ android {
 
     defaultConfig {
         // TODO: Specify your own unique Application ID (https://developer.android.com/studio/build/application-id.html).
-        applicationId = "com.example.dailyou"
+        applicationId = "net.stefwill.dailyou"
         // 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