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.

.gitignore

@@ -39,6 +39,9 @@ app.*.symbols
 # Obfuscation related
 app.*.map.json
 
+# LLM model files
+*.bin
+
 # Android Studio will place build artifacts here
 /android/app/debug
 /android/app/profile