Android over ADB, wireless

modules/home/apps/android.nix: adb, scrcpy and uad-ng, for looking inside the phone from this machine and cleaning it up.

Why ADB and not SFTP

The goal was a slow phone with too much installed. Apps and their data live under /data, which is closed to SFTP and to MTP without root: either one only sees shared storage (/sdcard: photos, Downloads, WhatsApp media). So SFTP can find big files but can never say which app holds 8 GB, and cannot uninstall anything. ADB sees both, and removes packages, including system bloat.

What the module does NOT need

• programs.adb: it has no effect anymore. systemd 258 ships the uaccess rules for ADB devices, so the USB ACL goes to whoever is logged in on the seat, with no adbusers group.
• A firewall port: in wireless debugging the PC dials OUT to the phone, both for adb pair and for adb connect. Nothing listens here.

Pairing (once per phone)

1. On the phone: Developer options, then Wireless debugging, then Pair device with pairing code. It shows an IP:port and a 6 digit code.

2. Here:

   adb pair 192.168.1.X:PAIRING_PORT   # asks for the code
   adb connect 192.168.1.X:PORT        # the port on the MAIN Wireless debugging screen
   adb devices                         # must list it as `device`, not `unauthorized`

The pairing port and the connect port are DIFFERENT, and both change every time wireless debugging is toggled. The pairing survives; only adb connect has to be repeated with the new port.

Measuring and cleaning

adb shell dumpsys diskstats            # per-app sizes: code, data, cache
adb shell du -h -d1 /sdcard | sort -h  # the heaviest folders in shared storage
adb shell pm list packages -3          # apps installed by me, not the system
adb shell pm trim-caches 999G          # clears every app's cache at once
adb uninstall <package>                # an app I installed
scrcpy                                 # the screen here, to click through settings

For system apps and vendor bloat, uad-ng. Each package carries a rating (Recommended, Advanced, Expert, Unsafe); stay on Recommended unless a package is known. Its removal is pm uninstall --user 0, which hides the app for the user and keeps the APK in the system partition, so it is reversible:

adb shell cmd package install-existing <package>

A factory reset also brings every removed system app back.