refactor: Reorganize config with use-package and optimize startup hooks

- Split monolithic init-package.el into focused modules
- Convert eager `:init` blocks to lazy `:hook`
- Consolidate UI settings and defer theme loading.
- Remove duplicated config between GUI and terminal paths.

lisp/init-prog.el

@@ -4,10 +4,22 @@
 
 ;;; Code:
 
-;; hs-minor-mode
-(add-hook 'prog-mode-hook 'hs-minor-mode)
+;; hideshow，折叠代码
+(use-package hideshow
+  :hook
+  (prog-mode . hs-minor-mode))
 
-;; flycheck
+;; xref，查找引用
+(use-package xref
+  :autoload xref-show-definitions-completing-read
+  :init
+  (when (executable-find "rg")
+    (setq xref-search-program 'ripgrep))
+
+  (setq xref-show-definitions-function #'xref-show-definitions-completing-read
+        xref-show-xrefs-function #'xref-show-definitions-completing-read))
+
+;; flycheck，语法检查
 (use-package flycheck)
 
 (use-package flycheck-guile
@@ -15,7 +27,6 @@
   (scheme-mode . (lambda ()
                    (require 'flycheck-guile))))
 
-;; consult-flycheck
 (use-package consult-flycheck)
 
 ;; tree-sitter