[nikitatar]

Summary

Updates DesktopDeployer in DeployBrush.kt to detect and support multi-user Android profiles (such as User 10 on Googlebook / Android Desktop devices) when deploying brushes from the AI Brush Designer CLI (/deploy).

Problem

• On standard single-user Android phones/emulators, adb shell am get-current-user returns 0, and /sdcard/ maps to /storage/emulated/0/, matching the foreground user's external_files FileProvider directory.
• On multi-user devices such as Googlebook, the active foreground Android user is 10, while /sdcard/ in adb still points to User 0 (/storage/emulated/0/) and Android FUSE isolation prevents shell (uid=2000) from directly writing to /storage/emulated/10/Android/data/....
• Consequently, launching Cahier with content://com.example.cahier.provider/external_files/new.brushfamily on User 10 failed with java.io.FileNotFoundException: open failed: ENOENT.

Solution

1. Query the active Android user via adb shell am get-current-user (defaulting to "0").
2. When currentUser == "0", preserve the existing external_files deployment behavior unchanged.
3. When currentUser != "0", copy the staged .brushfamily file into the active user's internal cache/shares/ directory using run-as com.example.cahier --user <currentUser>, launch MainActivity with --user <currentUser>, and import from content://com.example.cahier.provider/shared_files/<file> (already defined in app/src/main/res/xml/filepaths.xml).

Testing

• Verified /deploy end-to-end from the AI Brush Designer CLI on a Googlebook running as Android User 10.
• Verified :tools:test unit tests pass.

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[maxmmitchell]

LGTM, will address style concerns on backport.

[cka-dev]

1 nit comment