refactor: clean up codebase by removing redundant comments

Remove unnecessary JSDoc comments and redundant explanations from components, types, and data files. Simplify code structure while maintaining functionality.

Clean up language handling logic in components by removing redundant comments and simplifying state management. Move type imports to dedicated type import statements where applicable.

src/i18n/translations.ts

@@ -1,25 +1,9 @@
-/**
- * Translations module
- * Contains all translation data for the application
- */
-
-/**
- * Available languages in the application
- */
 export const languages = {
   en: 'English',
   zh: '简体中文',
 } as const;
 
-/**
- * Default language for the application
- */
 export const defaultLang = 'en';
-
-/**
- * Structured translations data
- * Organized by language and feature area
- */
 export const translations = {
   en: {
     nav: {