feat: Installer choice for users

[bikram-agarwal]

Add choice of installers 🔧

Summary

Adds a third installer option alongside Stock and Shizuku - a Legacy installer mode. This lets users delegate APK installations to an external installer app (e.g. InstallerX, App Manager) via a custom ContentProvider, bypassing Android's "Install Unknown Apps" restriction for the source app.

What's included

• Installer mode selector in Settings - segmented button to switch between Stock, Shizuku, and Legacy
• Installer app chooser - bottom sheet picker showing all compatible installer apps with their icons
• CacheContentProvider - serves APKs from internal cache via content:// URIs with world-readable permissions
• Install result detection - native BroadcastReceiver listens for ACTION_PACKAGE_ADDED / ACTION_PACKAGE_REPLACED to confirm installation success back to the app
• Settings migration - existing users with Shizuku enabled won't lose their preference on upgrade

Screenshot

Why this matters 🛡️

Users with Android's Advanced Protection enabled cannot grant "Install Unknown Apps" permission to any app. This feature provides a clean workaround by routing installations through a privileged installer that already has root/Shizuku access, without requiring any new app permissions.

Files changed (8)

• AndroidManifest.xml - CacheContentProvider declaration + package visibility queries
• CacheContentProvider.kt - Custom ContentProvider for serving cached APKs
• MainActivity.kt - MethodChannel bridge for installer queries and install intent dispatch
• installer_provider.dart - Dart-side installer channel wrapper
• settings_provider.dart - installerMode setting + migration from old useShizuku boolean
• settings.dart - Installer mode UI (SegmentedButton + legacy installer picker)
• apps_provider.dart - Legacy install flow integration
• en.json - 7 new translation keys (other locales welcome)

[victordou]

Great feature, free to change any installer, can't wait!

[ImranR98]

Have you tested to see if this works for background updates? This is a pretty big PR with native code, might take a while for me to get around to checking fully.

[bikram-agarwal]

Hi. No, I hadn't tested background updates. I always disable background updates on all my stores, since I like to read changelogs before updating.

I tried these steps now:

• Enabled background update in settings.
• Update checking interval: 15 minutes.
• Saw that there is an update available for WAEnhancer.
• Left the phone on desk for 20 minutes, didn't interact.
• Picked up the phone after 20 minutes - nothing had changed, no update installation had happened.

Maybe we can add a warning that background update installation may not be possible with Legacy mode.