KTailctl v0.18.0

This release fixes various crashes of KTailctl, fixes sendinf of files with Taildrop send, hides some currently broken features and provides the user with help (e.g. when he is logged out).

Changes

• Provide command to fix issues in notification banner (e.g. when being logged out)
• Reimplement a working Taildrop send functionality
• Add LLVM 19 build to GitHub actions
• Remove nlohmann_json git submodule
• Stabilize linting using pre-commit hooks in nix devenv
• Set exit nodes using DNS name instead of IP
• Hide currently broken features (statistics page and taildrop receiver in settings)

Bugfixes

• Fix notification banners in main window
• Fix crash on startup when logged out of Tailscale
• Fix crash when setting exit node from sytem tray menu

Chores

• Go dependencies:
  • golang.org/x/net: v0.27.0 -> v0.29.0
  • tailscale.com: v1.70.0 -> v1.74.0
• GitHub action dependencies:
  • actions/setup-go: v5.0.1 -> v5.0.2
  • cachix/install-nix-action: v27 -> v29