feat: implement email keyword management with color tagging

- Introduced a new settings section for managing email keywords (labels/tags) with associated colors.
- Updated email context menu, viewer, and list item components to support the new keyword system.
- Refactored color tag handling to accommodate both new $label: and legacy $color: prefixes.
- Added utility functions for retrieving email color tags based on keywords.
- Enhanced localization files to include translations for the new keyword management features.
- Updated the settings store to manage keyword definitions, including add, update, delete, and reorder functionalities.
- Added tests for the new keyword handling logic.

tailwind.config.ts

@@ -6,6 +6,7 @@ export default {
     "./pages/**/*.{js,ts,jsx,tsx,mdx}",
     "./components/**/*.{js,ts,jsx,tsx,mdx}",
     "./app/**/*.{js,ts,jsx,tsx,mdx}",
+    "./stores/**/*.{js,ts,jsx,tsx}",
   ],
   theme: {
     extend: {