Stylix unconditionally imports all target modules, which expect certain
program options to exist even when those programs aren't enabled. This
causes evaluation errors.
Add stylix-compat.nix with stub options for:
- programs.neovim.initLua (maps to extraLuaConfig)
- programs.opencode.tui/themes
Also:
- Disable neovim/neovide stylix targets (we deploy theme lua via theme-loader)
- Set autoEnable = false to only enable explicitly listed targets
- Enable programs.neovim to satisfy stylix's neovim target
- Update stylix to latest version
Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>