Armbian advances kernel support, desktop stack, and board coverage

This Armbian quarterly release introduces mainline Linux 7.0 across all major SoC families, with edge branches now tracking 7.1-rc and extensive patch updates for 6.18.x.

The desktop subsystem was fully rebuilt using a YAML-driven, tier-based system in armbian-config, adding support for several new desktop environments and architectures.

Major board and platform additions include mainline support for Arduino UNO Q, Mekotronics R58S2, NanoPC-T6 LTS Plus, Ariaboard Photonicat 2, and more.