feat(frontend): Implement notification settings with separate drawers and improved design.

- Add shadcn/ui drawer and switch components
- Create NotificationFiltersDrawer for editing notification filters
- Create DiscordConfigDrawer with test functionality
- Create TelegramConfigDrawer with test functionality
- Add reusable EditButton component for consistent design language
- Refactor Settings page to use separate drawers per configuration type
- Remove test notifications card, integrate testing into service drawers
- Simplify notification service status indicators for cleaner UI
- Remove redundant service descriptions for streamlined layout

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-Authored-By: Claude <noreply@anthropic.com>

frontend/package.json

@@ -24,6 +24,7 @@
     "@radix-ui/react-select": "^2.2.6",
     "@radix-ui/react-separator": "^1.1.7",
     "@radix-ui/react-slot": "^1.2.3",
+    "@radix-ui/react-switch": "^1.2.6",
     "@radix-ui/react-tabs": "^1.1.13",
     "@radix-ui/react-toggle": "^1.1.10",
     "@radix-ui/react-toggle-group": "^1.1.11",