Feature Request: `device-upgrade` command for device-installed app updates

[benedictjohannes]

Summary

Add a new subcommand, device-update (or device-upgrade), that uses a connected device's internal package metadata to identify and install pending updates specifically for apps originally managed by F-Droid.

Motivation

Currently, fdroidcl install -u requires an app ID or a manual list. For users with multiple devices, upgrading "everything" currently requires an "involved" workflow:

1. Running fdroidcl scan to find what's there.
2. Manually piping or scripting that list into fdroidcl install.
3. Managing the "Hybrid Install" risk where F-Droid might try to overwrite a Play Store version of the same app (which fails due to signatures but wastes time/bandwidth).

A device-driven approach removes this friction by letting the phone's own "Installer" metadata act as the filter. This would allow fdroidcl to act as a desktop-powered Update All functionality currently available in F-Droid Android client, which would add a significant value as Google's identification policy make on-device sideloading increasingly cumbersome.

Proposed Implementation

1. Command Workflow

• Step A (Device Selection): * If ANDROID_SERIAL is set, use it. If multiple devices are detected and no serial is provided, offer a simple interactive picker (TUI) to select the target.

• Step B (The "Installer" Filter): * Run adb shell pm list packages -i and filter for lines containing installer=org.fdroid.fdroid. This ensures we only attempt to update apps that the user has intentionally placed on the F-Droid track.

• Step C (Delta Comparison): * Compare the versionCode of the filtered device packages against the local fdroidcl index.

• Step D (Batch Execution): * Download and execute adb install -r -i org.fdroid.fdroid for the identified updates.

2. Proposed CLI Interface

# Standard usage: auto-selects if one device is connected
$ fdroidcl device-update

# Example output with interactive picker:
# ? Select device:
# > [RFCT...] Samsung S25 Ultra
#   [TAB9...] Samsung Tab S9 Plus

# Result:
# [✓] org.journiv.app: 1.0.2 -> 1.0.5
# [✓] org.syncthing.android: 1.27.2 -> 1.27.3
# Done. 2 apps updated.

# Exclude specific apps via substring match
$ fdroidcl device-update -e syncthing -e "work.app"

# Update the index before performing the update
$ fdroidcl device-upgrade -u

# Override the default org.fdroid.fdroid installer filtering
$ fdroidcl device-upgrade -i org.fdroid.basic

Technical Details

• Exclusion Logic: The -e flag should support multiple instances and perform a case-insensitive substring match against the package ID.
• Installer Preservation: Using the -i org.fdroid.fdroid flag during the adb install phase is recommended to maintain the "Installer" metadata on the device for future cycles.
• TUI: For the device picker, utilizing a lightweight TUI library (or simply mimicking the existing devices output with an index) would keep dependencies minimal.

I'll be happy to contribute a PR to implement this functionality if this direction align with the project's goals.