BetterKnownInstalled v1.6.0 is out

This is the stateful backup release. No more blind patching every boot.

What's new:

- metadata.db — first boot builds a per-app database of your original installer/uid/initiator values. Subsequent boots only prune dead entries and patch what's new. Boot time drops from ~1s to ~50ms.
- Proper uninstall — uninstall.sh now restores each app's exact original metadata from the DB. Apps no longer stay locked as com.android.vending after you remove the module.
- Atomic writes — everything is staged to .tmp and moved into place. No more half-written packages.xml on crash.
- riscv64 support added.

Gone:
- Rotating XML backups are dead weight. The DB is your backup. One packages.xml.safety copy is kept for crash recovery only.

Upgrade note:
If you're coming from v1.5.x, the DB is built from your already patched packages.xml. Previously patched apps will keep their patched values recorded as "originals" — uninstall won't revert those specific apps to their true pre-BKI state. Anything you install after v1.6.0 is fully tracked and will restore correctly.

Update and reboot. Feedback welcome as always.