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.

init.el

@@ -18,6 +18,8 @@
       (load "init-proxy" t)
       (require 'init-startup)
       (require 'init-elpa)
+      (require 'init-base)
+      (require 'init-edit)
       (require 'init-package)
       (require 'init-org)
       (require 'init-prog)