Introduce a runtime UI language switcher and add Japanese/Korean locale support. Added _locales/ja and _locales/ko messages, updated en and zh_CN message files with new language-related keys and sendImage label. Implemented dynamic i18n handling: new i18n.js supports override messages, persistent uiLanguage in storage, and emits i18n:changed; background.js now loads override locales, updates context menu titles and listens for storage changes. Integrated dayjs locales (js/ja.js, js/ko.js) and made oper.js use a unified msg() helper and react to language changes. Added language selector UI in popup.html and styling in css/main.css.
Introduce an upload attachments panel with styles, localization and client-side management. Added new i18n keys (EN/ZH) and refactored js/i18n.js to helper setters for text/placeholder/title. popup.html and css/main.css add the upload-list UI and styles. oper.js implements rendering, drag-and-drop reorder, deletion (calls DELETE api with token), storage persistence (resourceIdList), escapeHtml sanitization, and sync change handling; it also fixes a config check (repo -> apiTokens), stores filename from upload responses, handles attachments/resources compatibility, and clears the list after sending a memo. Overall this enables reorderable, deletable uploaded attachments with proper localization and tooltips.
jonny