nixpkgs moves from 2026-08-04 to 2026-10-17. Also updated: anotherim,
lanzaboote, nix-amd-ai, nix-flatpak and sops-nix, plus their
transitive inputs.
Assisted-by: Claude:opus-5-5
Add nix-flatpak flake input and modules/gaming.nix managing Flatpak
remotes/packages declaratively: Bolt (Jagex launcher for RS3/OSRS) and
Sober (Roblox). Add Heroic and hyperplay-ext, plus Proton-GE for Steam.
Drops the old imperative runescape-launcher.
