v2.0.0

The first release under the DirtyFragX name. The exploit engine is unchanged from 1.16 - everything
below is the app around it.

App - new interface

• The app is split into two pages behind a pager: Home, which carries the run flow, and
  Settings, which collects the options that used to be spread across dialogs.
• The exploit now runs on its own screen (RunActivity) instead of inside a modal dialog, so the
  progress, the log and the device information stay readable while it runs.
• Home is a draggable card stack: the SU manager prerequisite and the current status sit above
  the run button, and the status pill follows Waiting / Running / Rooted / Verification /
  Verified / Failure / Reboot required.
• The log can be copied in one tap, and Advanced logs switches the run panel from the summary to
  the full output.

App - settings

• Light and dark themes, plus an accent tone that recolours buttons, icons and highlights.
• Language switch between English and Simplified Chinese.
• Expert mode hides autorun and auto soft reboot behind an explicit toggle.
• KernelSU module enable/disable, soft reboot, and a copyable device info block (device, system,
  kernel, arch, fingerprint).
• Tutorial opens the walkthrough page; the about section links to this project and to the
  original DirtyFrag repository.

App - updates and announcements

• In-app update check: it reads the latest release, downloads the APK and hands it to the system
  installer, and reports a failed download, a non-APK payload or a missing "install unknown apps"
  permission separately.
• Announcement dialog for one-off notices, with Got it and a shortcut to the tutorial.

App - identity

• Renamed from DFRoot to DirtyFragX, with a new adaptive launcher icon (black foreground on white,
  plus a monochrome layer for Android 13+ themed icons) and a console banner that reads
  DIRTYFRAGX.
• GPL-3.0 licence text added to the repository.

Build and release

• The Build workflow now belongs to this project: eight LKMs / <kmi> jobs build the kernel
  modules, build-dfroot assembles the APK, and a v* tag publishes DirtyFragX-<tag>.apk with
  notes taken from this file.
• Release builds are signed with app/keystore.jks, restored from the KEYSTORE secret in CI, so
  every APK from this fork shares one signing identity. Pull-request builds fall back to the debug
  key instead of failing.
• The APK is always written as dirtyfragx.apk, and the GitHub release is mirrored to Gitee.