[anthonyportugal]

Adds Neovim with LazyVim to the opt-in dev layer, colored from the active palette, and makes it the editor when installed. Merge without squash to keep the commits.

Changes

• LazyVim (nvim stow package) – the official starter bootstrap plus extras for the stack: TypeScript/React, Vue, Angular, Astro, Tailwind, Go, Rust, JSON, YAML, TOML, Docker, Markdown, Prettier, ESLint, DAP and the test runner. The dev layer adds neovim, tree-sitter-cli, gcc, ripgrep, fd and unzip. lazy-lock.json stays local to ~/.config/nvim, outside the repo.
• Palette colors – a new shared template, themes/templates/nvim/palette.lua, is read from the state path by colors/dotfiles.lua, which builds the highlights with mini.base16 and refines them with the palette roles. Without a rendered palette, Neovim uses tokyonight. A reload.d/nvim hook re-applies the colorscheme in running instances on dotfiles-theme set.
• Editor – with nvim installed, the dev zsh file replaces only core's micro defaults for EDITOR/VISUAL; an editor the user exported is kept. GIT_EDITOR follows the result.
• cli no longer claims Neovim in its description and prune list.

Review notes

• Breaking changes: none. Everything is in the opt-in dev layer; without it micro stays the editor.
• colors/dotfiles.lua is loaded against all 50 palettes under a LuaJIT stub of vim. The tests skip it, with a visible SKIP, when luajit is absent.
• Not exercised in CI or locally: a real Neovim start (plugin install, Mason servers). It needs a manual check after installing the dev packages.

Testing

• tests/smoke.sh and shellcheck -x pass locally on the final commit.
• New behavior was checked RED → GREEN in tests/optional-layers-smoke.sh and tests/theme-apps-smoke.sh. Mutations (colors_name, socket check, tokyonight fallback, manifest entries) fail the tests.