Adds an optional session filter bar to the left sidebar with title search across parent/child sessions and a scoped Select All. Introduces multi-select checkboxes, bulk delete with clear selection controls, and confirmation dialogs for both single and bulk deletions using the existing alert dialog flow. Updates session i18n strings across supported locales.
Converts hardcoded UI copy to i18n keys across the app, adds global translation for non-component modules, and splits the English catalog into feature modules with duplicate-key detection.
Cmd+Shift+[ and Cmd+Shift+] now cycle through visible sessions only (parents + expanded children) and no longer include Instance Info. Sidebar session list auto-scrolls to keep the active session row in view.
Show sessions as parent/child threads with expand/collapse and improved agent row styling. Keep a 5-session cache to avoid refetching messages when switching between recently visited sessions.
- Add clipboard utility with fallback for non-secure contexts
- Implement modern Clipboard API with document.execCommand fallback
- Update copy buttons in code blocks, markdown, messages, and session list
- Add proper error handling and user feedback for copy operations
Fixes issue where copy buttons did not work in web browsers served over HTTP or without Clipboard API support
