nvim: fix startup errors, add language + project-run support

Startup errors:
- catppuccin: the bufferline integration moved to catppuccin.special.bufferline
- lspconfig-extended: drop the removed LazyVim keymaps API for
  opts.servers["*"].keys, and move remove-workspace-folder to <leader>clR
  so it stops colliding with LspRestart on <leader>clr
- options: lazyvim_cmp = "blink" is not a valid value, it is "blink.cmp"

Language support (python, c/cpp, rust, zephyr, and the common ones) via
lazyvim.json extras: dap.core, clangd, cmake, docker, git, json, rust,
toml, yaml.

- lang/zephyr.lua: gated entirely on ZEPHYR_BASE / ZEPHYR_SDK_INSTALL_DIR /
  GNUARMEMB_TOOLCHAIN_PATH, returning {} when none are set, so it is inert
  on machines without Zephyr. Nothing is hardcoded: the clangd
  --query-driver globs are built from those vars, falling back to resolving
  the cross-gcc through exepath()+fs_realpath(). Adds devicetree/kconfig
  treesitter and filetypes (*.overlay, Kconfig.*, prj.conf, *_defconfig).
- clangd/config.yaml: strip the GCC-only flags Zephyr emits into
  compile_commands.json (-fno-printf-return-value, -mfp16-format=*, ...),
  which clang rejects as "Unknown argument". Remove only drops flags that
  are present, so it is a no-op for native builds. Takes a built Zephyr app
  from 15 diagnostics to 0, with CONFIG_* resolving into the generated
  autoconf.h.
- npm-servers.lua: npm is not installed here, so yaml/docker servers failed
  to install on every startup and to spawn on every matching file. Sets
  both enabled = false and mason = false for servers whose binary is
  missing from PATH and from mason/bin.

Project runner under <leader>R (<leader>r is refactoring), dispatching on
the detected project type -- zephyr, rust, python, cmake, make:

  Rr run project   Rb build   Rt test   RF build+flash   Rf run file
  Rk configure     Rc clean   Rs select target/board     Ri info

Zephyr boards are picked with vim.ui.select over `west boards`, cached per
scan and persisted per project root under stdpath("state"), never written
into the project. A build with no board set prompts first, then proceeds.
Detection walks up from the last real file buffer, tracked by an autocmd,
because a terminal opened by one of these verbs would otherwise become the
buffer detection ran from.

Also <leader>b1..b9/b0 jump to buffer N (ordinal, no longer skipping the
current one) and <leader>b<Left>/<Right> cycle.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01StGBghPW9Dm7z7uj2VNWHr

nvim/lua/plugins/extras/lang/zephyr.lua

@@ -0,0 +1,115 @@
+-- Zephyr RTOS support.
+--
+-- This extra is driven entirely by Zephyr's own environment variables and is
+-- inert unless one of them is set, so it costs nothing on a machine that does
+-- no Zephyr work and needs no per-host editing.
+--
+--   ZEPHYR_BASE               the zephyr repo -- presence of this enables the extra
+--   ZEPHYR_SDK_INSTALL_DIR    Zephyr SDK root (toolchain variant "zephyr")
+--   GNUARMEMB_TOOLCHAIN_PATH  toolchain root  (variant "gnuarmemb")
+--   ZEPHYR_TOOLCHAIN_VARIANT  which of the above is in use
+--
+-- Zephyr is otherwise "C + CMake + Kconfig + devicetree", so clangd and cmake
+-- do the heavy lifting. What clangd cannot work out unaided is the built-in
+-- include paths of a cross compiler, hence --query-driver.
+-- (Zephyr's build/compile_commands.json is found by clangd on its own: it
+-- searches ./ and ./build of each parent directory.)
+
+local zephyr_base = os.getenv("ZEPHYR_BASE")
+local sdk_dir     = os.getenv("ZEPHYR_SDK_INSTALL_DIR")
+local gnuarmemb   = os.getenv("GNUARMEMB_TOOLCHAIN_PATH")
+
+-- Not a Zephyr environment -> contribute nothing.
+if not (zephyr_base or sdk_dir or gnuarmemb) then
+  return {}
+end
+
+--- Toolchain globs for clangd's --query-driver, taken from the Zephyr vars.
+--- Falls back to whatever cross gcc the environment puts on $PATH when the
+--- toolchain variables are not set (as with a distro-packaged toolchain).
+---@return string[]
+local function query_driver_globs()
+  local globs, seen = {}, {}
+  local function add(p)
+    if p and p ~= "" and not seen[p] then
+      seen[p] = true
+      globs[#globs + 1] = p
+    end
+  end
+
+  -- Zephyr SDK: <sdk>/<target>-zephyr-elf/bin/<target>-zephyr-elf-gcc
+  if sdk_dir then
+    add(sdk_dir .. "/*/bin/*-gcc")
+  end
+
+  -- gnuarmemb variant: <root>/bin/arm-none-eabi-gcc
+  if gnuarmemb then
+    add(gnuarmemb .. "/bin/*-gcc")
+  end
+
+  -- No toolchain var set: resolve the cross compiler through $PATH instead of
+  -- assuming a prefix, and glob its real directory.
+  if #globs == 0 then
+    for _, cc in ipairs({
+      "arm-zephyr-eabi-gcc",
+      "arm-none-eabi-gcc",
+      "riscv64-zephyr-elf-gcc",
+      "xtensa-espressif_esp32-elf-gcc",
+    }) do
+      local exe = vim.fn.exepath(cc)
+      if exe ~= "" then
+        add(vim.fs.dirname(vim.uv.fs_realpath(exe) or exe) .. "/*-gcc")
+      end
+    end
+  end
+
+  return globs
+end
+
+return {
+  -- Syntax for the two Zephyr-specific languages
+  {
+    "nvim-treesitter/nvim-treesitter",
+    opts = { ensure_installed = { "devicetree", "kconfig" } },
+  },
+
+  {
+    "neovim/nvim-lspconfig",
+    -- Filetype detection Neovim does not ship with
+    init = function()
+      vim.filetype.add({
+        extension = {
+          overlay = "dts", -- board/shield overlays are devicetree
+        },
+        filename = {
+          ["prj.conf"] = "kconfig",
+          ["west.yml"] = "yaml",
+        },
+        pattern = {
+          ["Kconfig.*"] = "kconfig", -- Kconfig.foo, Kconfig.defconfig, ...
+          [".*/boards/.*%.conf"] = "kconfig",
+          [".*/prj_.*%.conf"] = "kconfig",
+          [".*_defconfig"] = "kconfig",
+        },
+      })
+    end,
+
+    opts = function(_, opts)
+      opts.servers = opts.servers or {}
+      local clangd = opts.servers.clangd or {}
+
+      local drivers = query_driver_globs()
+      if #drivers > 0 then
+        clangd.cmd = clangd.cmd or { "clangd" }
+        table.insert(clangd.cmd, "--query-driver=" .. table.concat(drivers, ","))
+      end
+
+      -- Treat a west workspace / Zephyr app as a project root.
+      clangd.root_markers = clangd.root_markers or {}
+      vim.list_extend(clangd.root_markers, { "west.yml", ".west", "prj.conf", "CMakeLists.txt" })
+
+      opts.servers.clangd = clangd
+      return opts
+    end,
+  },
+}