dotfiles/.claude/tasks/0022-stylix-nord-theming.md

spec, blocked-by

spec	blocked-by
hyprland-desktop	0021-desktop-group-and-hyprland-session

What to build

Theme the whole new graphical layer Nord from a single source, and set the wallpaper.

Add Stylix as a flake input and a desktop theming module that drives colors, system fonts, and cursor from one Nord base16 scheme across the graphical surface (GTK, Qt, and the compositor colors), plus a single static Nord wallpaper set by Stylix. Scope Stylix to the graphical layer only: leave its targets for the existing terminal tools (nvim, tmux, fish) off so their established hand-themes stand unchanged. The theming is reversible per target, so individual surfaces can migrate toward or away from manual theming later.

Acceptance criteria

• Stylix is a flake input, wired into the host build.
• A desktop theming module resolves a single Nord base16 scheme and applies it to GTK, Qt, cursor, and system fonts.
• A single static Nord wallpaper is set by Stylix; no dynamic, animated, or cycling wallpaper.
• Stylix targets for nvim, tmux, and fish are off, leaving their existing themes untouched.
• neogaia builds green under nix flake check, and an eval probe confirms the resolved scheme is Nord.

Implementation Notes

• Wallpaper is a generated Nord gradient, not a shipped image. Stylix requires an image, and the spec asks only for "a single static Nord wallpaper". Rather than commit a binary blob or fetch one over the network at build time, the module draws a vertical gradient across the Nord Polar Night shades (#2E3440 → #3B4252) with ImageMagick. It is static, genuinely Nord, and fully reproducible with no external dependency beyond a cached build tool. Swapping in a picture later is a one-line change to image.

• The nvim target is nixvim, not neovim. nvim here is configured through nixvim, so the Stylix target that would theme it is nixvim. Disabling neovim would have been a no-op and left nvim themed.

• fish is disabled at two levels. fish is enabled both at system level (programs.fish, for /etc/shells and vendor completions) and in home-manager, so its theming has a target in each scope. Both are turned off, so the hand-written fish theme stands.

• Cursor generation switched on explicitly. home-manager now wants home.pointerCursor.enable set explicitly rather than inferring it from the presence of cursor settings, so the module sets it to silence the deprecation and keep the build warning-clean (bar the pre-existing benign nixvim nixpkgs.follows notice).

• System font pinned to JetBrains Mono. The acceptance criterion asks for "system fonts" without naming one, so the monospace is pinned to JetBrains Mono and the serif/sans/emoji families are left at Stylix's Nord-coherent defaults.

• Stylix module imported unconditionally. lib.nix adds inputs.stylix.nixosModules.stylix to every host's module set, matching how the other input modules are wired. It stays inert until stylix.enable is set, which only the theming module does, only when the desktop is on.