feat(tabs,bookmarks,dark-mode): enhance tab management and UX}
- Add tab drag-and-drop reordering with persistent order across restarts - Add tab renaming via right-click context menu with custom labels - Add tab pinning to prevent accidental closure (with pin icon indicator) - Add restore last closed tab feature (keeps up to 10 in history) - Add per-tab zoom level with independent persistence per tab - Add bookmark folders with nested submenus using / separator - Add bookmark manager dialog with search, inline editing, and delete - Add bookmark import/export as JSON files - Add dark mode "Follow system" option that tracks OS theme changes - Add granular session cleaner (cookies, cache, or everything per tab) - Add multi-monitor window position safety for off-screen recovery - Use lighter dark mode palette based on Microsoft Fluent Design - Prevent blank page after reload by validating saved URLs - Enforce single instance (remove multiple instances option) - Remove reading mode (F11 fullscreen is sufficient) - Remove auto-launch on login (not supported on Linux) - Remove "quirks" wording from dark theme labels - Remove semver dependency for instance lock check - Update all 30 translation files with new UI strings - Bump version to v2026.4.118