Add standalone Neovim Lua config

Replace the neovim stow package's symlink into vim/.vim with a real,
independent Lua config: init.lua + lua/config/* (options, keymaps,
autocmds, lazy.nvim bootstrap) + lua/plugins/*.lua (one file per plugin
group).

- Plugin manager: lazy.nvim (self-bootstrapping, no submodule needed).
- Carries over every plugin from the vimrc as-is: vim-airline (+ themes,
  tmuxline), vim-janah colorscheme, nerdtree, vim-signify, nerdcommenter,
  ale, vim-fugitive, quick-scope, ctrlp.vim, claude-code.nvim, plus
  vim-ansible-yaml/vim-terraform gated the same way the vimrc gated them
  (executable() checks, now as lazy.nvim `cond` functions).
- Replaces YouCompleteMe + jedi-vim entirely with nvim-lspconfig +
  mason.nvim + mason-lspconfig.nvim (ensure_installed: pyright, lua_ls,
  bashls, terraformls, yamlls, ts_ls, cssls, html; clangd enabled
  directly since it's already on PATH via Xcode CLT) and blink.cmp for
  completion (+ friendly-snippets), with blink's LSP capabilities merged
  into every server's default config.
- ALE stays as a pure linter/fixer (g:ale_disable_lsp = 1) so it doesn't
  duplicate nvim-lspconfig's diagnostics/hover/go-to-definition.
- Ports the vimrc's general settings/functions (options, window-nav
  keymaps, arrow-key disabling, StripTrailingWhitespace, AppendModeline,
  the git->Git abbreviation) to Lua; drops the w!! sudo-save abbreviation
  (vimrc's own comment notes it doesn't work under Neovim) and the
  reload-vimrc-on-save autocmd (no clean Lua equivalent).

Vim's own vimrc, ftplugin/python.vim, and plugin installs are completely
untouched and unaffected by this change.

1 files changed, 33 insertions, 0 deletions

diff --git a/neovim/.config/nvim/lua/plugins/filetree.lua b/neovim/.config/nvim/lua/plugins/filetree.lua
new file mode 100644
index 0000000..cdee9f7
--- /dev/null
+++ b/neovim/.config/nvim/lua/plugins/filetree.lua
@@ -0,0 +1,33 @@
+return {
+  "preservim/nerdtree",
+  lazy = false,
+  config = function()
+    -- Open NERDTree when no file is specified; quit when it's the last window
+    local augroup = vim.api.nvim_create_augroup("nerdtree_auto", { clear = true })
+
+    vim.api.nvim_create_autocmd("StdinReadPre", {
+      group = augroup,
+      callback = function()
+        vim.g.std_in = 1
+      end,
+    })
+
+    vim.api.nvim_create_autocmd("VimEnter", {
+      group = augroup,
+      callback = function()
+        if vim.fn.argc() == 0 and vim.g.std_in == nil then
+          vim.cmd("NERDTree")
+        end
+      end,
+    })
+
+    vim.api.nvim_create_autocmd("BufEnter", {
+      group = augroup,
+      callback = function()
+        if vim.fn.winnr("$") == 1 and vim.bo.filetype == "nerdtree" then
+          vim.cmd("quit")
+        end
+      end,
+    })
+  end,
+}