fix(neovim): migrate LSP config to native vim.lsp.config API

Replace deprecated require("lspconfig") setup with the Neovim 0.11+
native vim.lsp.config/vim.lsp.enable API. Clangd config now lives in
lsp/clangd.lua instead of the old plugins/lspconfig.lua +
configs/lspconfig.lua pair.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

archduino-guide.md

@@ -298,15 +298,10 @@ return {
 }
 ```
 
-Create `~/.config/nvim/lua/plugins/lsp.lua`:
+Create `~/.config/nvim/lsp/clangd.lua` (native Neovim 0.11+ LSP config):
 
 ```lua
 return {
-  {
-    "neovim/nvim-lspconfig",
-    opts = {
-      servers = {
-        clangd = {
   cmd = {
     "clangd",
     "--background-index",
@@ -314,13 +309,16 @@ return {
     "--header-insertion=iwyu",
     "--completion-style=detailed",
   },
-        },
+  filetypes = { "c", "cpp", "objc", "objcpp", "cuda", "arduino" },
-      },
-    },
-  },
 }
 ```
 
+Enable the server (e.g. in `init.lua` or a plugin file):
+
+```lua
+vim.lsp.enable("clangd")
+```
+
 ---
 
 ## 5. Arduino CLI

lib/neovim.sh

@@ -143,34 +143,11 @@ return {
 }
 LUA
 
-# ── LSP (clangd) ───────────────────────────────────────────────
+# ── LSP (clangd) — native vim.lsp.config (Neovim 0.11+) ──────
-mkdir -p "$NVIM_CFG/lua/configs"
+mkdir -p "$NVIM_CFG/lsp"
 
-cat >"$NVIM_CFG/lua/plugins/lspconfig.lua" <<'LUA'
+cat >"$NVIM_CFG/lsp/clangd.lua" <<'LUA'
 return {
-  {
-    "neovim/nvim-lspconfig",
-    config = function()
-      require("nvchad.configs.lspconfig").defaults()
-      require "configs.lspconfig"
-    end,
-  },
-}
-LUA
-
-cat >"$NVIM_CFG/lua/configs/lspconfig.lua" <<'LUA'
-local configs = require "nvchad.configs.lspconfig"
-
-local on_attach = configs.on_attach
-local on_init = configs.on_init
-local capabilities = configs.capabilities
-
-local lspconfig = require "lspconfig"
-
-lspconfig.clangd.setup {
-  on_init = on_init,
-  on_attach = on_attach,
-  capabilities = capabilities,
   cmd = {
     "clangd",
     "--background-index",
@@ -178,9 +155,19 @@ lspconfig.clangd.setup {
     "--header-insertion=iwyu",
     "--completion-style=detailed",
   },
+  filetypes = { "c", "cpp", "objc", "objcpp", "cuda", "arduino" },
 }
 LUA
 
+# Enable clangd via native API
+cat >"$NVIM_CFG/lua/plugins/lspconfig.lua" <<'LUA'
+vim.lsp.enable("clangd")
+return {}
+LUA
+
+# Clean up legacy configs/lspconfig.lua if present
+rm -f "$NVIM_CFG/lua/configs/lspconfig.lua"
+
 # ── Keymaps ─────────────────────────────────────────────────────
 cat >"$NVIM_CFG/lua/mappings.lua" <<'LUA'
 require "nvchad.mappings"