Add Emacs desktop provisioning and dev toolchain packages

Install Emacs and copy the desktop .emacs.d config so the editor setup is managed with the rest of desktop dotfiles. Add vterm/build/debug dependencies plus C/C++ and Go tooling needed by the configured workflow.

dotfiles/desktop/.emacs.d/lisp/lang/c.el

@@ -0,0 +1,39 @@
+;; c.el -*- lexical-binding: t; -*-
+
+;; C / C++ fallback style (Linux-like)
+(setq c-default-style "linux"
+      c-basic-offset 4
+      tab-width 8)
+
+(add-hook 'c-mode-common-hook
+          (lambda ()
+            (setq indent-tabs-mode t)))
+
+;; Tree-sitter C/C++
+(setq c-ts-mode-indent-offset 4)
+(setq c++-ts-mode-indent-offset 4)
+
+(with-eval-after-load 'lsp
+    ;; Clangd configurations
+  (setq lsp-clients-clangd-args
+	'("--background-index"
+	  "--clang-tidy"
+	  "--completion-style=detailed"
+	  "--header-insertion=never"
+	  "--header-insertion-decorators"
+	  "--pch-storage=memory"
+	  "--log=error"
+	  "--ranking-model=heuristics"
+	  "--malloc-trim"
+	  "--limit-results=500"
+	  "--limit-references=2000")))
+
+(with-eval-after-load 'dap-mode
+  (require 'dap-cpptools))
+
+(add-hook 'c-ts-mode-hook #'fscotto/disable-c-formatting)
+(add-hook 'c-mode-hook    #'fscotto/disable-c-formatting)
+
+(provide 'c)
+
+;;; c.el ends here