feat: add devtools (tree-sitter, neovim, formatter, CLI commands)

- Add tree-sitter grammar for syntax highlighting
- Add Neovim plugin with syntax, LSP integration, and commands
- Add code formatter (lux fmt) with check mode
- Add CLI commands: fmt, check, test, watch, init
- Add project initialization with lux.toml template

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

editors/nvim/lua/lux/init.lua

@@ -0,0 +1,163 @@
+-- Lux language support for Neovim
+-- Provides LSP configuration and utilities
+
+local M = {}
+
+-- Default configuration
+M.config = {
+  -- Path to lux binary (will search PATH if not set)
+  lux_binary = nil,
+  -- Enable LSP
+  lsp = {
+    enabled = true,
+    -- Auto-start LSP when opening .lux files
+    autostart = true,
+  },
+  -- Formatting options
+  format = {
+    -- Format on save
+    on_save = false,
+  },
+}
+
+-- Find lux binary
+local function find_lux_binary()
+  if M.config.lux_binary then
+    return M.config.lux_binary
+  end
+  -- Try to find in PATH
+  local handle = io.popen("which lux 2>/dev/null")
+  if handle then
+    local result = handle:read("*a"):gsub("%s+", "")
+    handle:close()
+    if result ~= "" then
+      return result
+    end
+  end
+  -- Try common locations
+  local common_paths = {
+    "./result/bin/lux",
+    "~/.local/bin/lux",
+    "/usr/local/bin/lux",
+  }
+  for _, path in ipairs(common_paths) do
+    local expanded = vim.fn.expand(path)
+    if vim.fn.executable(expanded) == 1 then
+      return expanded
+    end
+  end
+  return "lux" -- Fallback, hope it's in PATH
+end
+
+-- Setup LSP
+function M.setup_lsp()
+  local lux_binary = find_lux_binary()
+
+  -- Check if lspconfig is available
+  local ok, lspconfig = pcall(require, "lspconfig")
+  if not ok then
+    vim.notify("lspconfig not found. Install nvim-lspconfig for LSP support.", vim.log.levels.WARN)
+    return
+  end
+
+  local configs = require("lspconfig.configs")
+
+  -- Register lux LSP if not already registered
+  if not configs.lux_lsp then
+    configs.lux_lsp = {
+      default_config = {
+        cmd = { lux_binary, "lsp" },
+        filetypes = { "lux" },
+        root_dir = function(fname)
+          return lspconfig.util.find_git_ancestor(fname)
+            or lspconfig.util.root_pattern("lux.toml")(fname)
+            or vim.fn.getcwd()
+        end,
+        settings = {},
+      },
+    }
+  end
+
+  -- Setup the LSP
+  lspconfig.lux_lsp.setup({
+    on_attach = function(client, bufnr)
+      -- Enable completion
+      vim.bo[bufnr].omnifunc = "v:lua.vim.lsp.omnifunc"
+
+      -- Key mappings
+      local opts = { noremap = true, silent = true, buffer = bufnr }
+      vim.keymap.set("n", "gd", vim.lsp.buf.definition, opts)
+      vim.keymap.set("n", "K", vim.lsp.buf.hover, opts)
+      vim.keymap.set("n", "gi", vim.lsp.buf.implementation, opts)
+      vim.keymap.set("n", "<C-k>", vim.lsp.buf.signature_help, opts)
+      vim.keymap.set("n", "gr", vim.lsp.buf.references, opts)
+      vim.keymap.set("n", "<leader>rn", vim.lsp.buf.rename, opts)
+      vim.keymap.set("n", "<leader>ca", vim.lsp.buf.code_action, opts)
+      vim.keymap.set("n", "[d", vim.diagnostic.goto_prev, opts)
+      vim.keymap.set("n", "]d", vim.diagnostic.goto_next, opts)
+
+      -- Format on save if enabled
+      if M.config.format.on_save then
+        vim.api.nvim_create_autocmd("BufWritePre", {
+          buffer = bufnr,
+          callback = function()
+            vim.lsp.buf.format({ async = false })
+          end,
+        })
+      end
+    end,
+    capabilities = vim.lsp.protocol.make_client_capabilities(),
+  })
+end
+
+-- Run current file
+function M.run_file()
+  local file = vim.fn.expand("%:p")
+  local lux_binary = find_lux_binary()
+  vim.cmd("!" .. lux_binary .. " " .. vim.fn.shellescape(file))
+end
+
+-- Format current file
+function M.format_file()
+  local file = vim.fn.expand("%:p")
+  local lux_binary = find_lux_binary()
+  vim.cmd("!" .. lux_binary .. " fmt " .. vim.fn.shellescape(file))
+  vim.cmd("edit!") -- Reload the file
+end
+
+-- Run tests
+function M.run_tests()
+  local lux_binary = find_lux_binary()
+  vim.cmd("!" .. lux_binary .. " test")
+end
+
+-- Start REPL in terminal
+function M.start_repl()
+  local lux_binary = find_lux_binary()
+  vim.cmd("terminal " .. lux_binary)
+end
+
+-- Setup function
+function M.setup(opts)
+  -- Merge user config
+  M.config = vim.tbl_deep_extend("force", M.config, opts or {})
+
+  -- Setup LSP if enabled
+  if M.config.lsp.enabled and M.config.lsp.autostart then
+    vim.api.nvim_create_autocmd("FileType", {
+      pattern = "lux",
+      callback = function()
+        M.setup_lsp()
+      end,
+      once = true,
+    })
+  end
+
+  -- Create user commands
+  vim.api.nvim_create_user_command("LuxRun", M.run_file, { desc = "Run current Lux file" })
+  vim.api.nvim_create_user_command("LuxFormat", M.format_file, { desc = "Format current Lux file" })
+  vim.api.nvim_create_user_command("LuxTest", M.run_tests, { desc = "Run Lux tests" })
+  vim.api.nvim_create_user_command("LuxRepl", M.start_repl, { desc = "Start Lux REPL" })
+end
+
+return M