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/src/components/ui/edit-button.tsx

@@ -0,0 +1,39 @@
+import { Edit3 } from "lucide-react";
+import { Button } from "./button";
+import { cn } from "../../lib/utils";
+
+interface EditButtonProps {
+  onClick?: () => void;
+  disabled?: boolean;
+  className?: string;
+  size?: "default" | "sm" | "lg" | "icon";
+  variant?: "default" | "destructive" | "outline" | "secondary" | "ghost" | "link";
+  children?: React.ReactNode;
+}
+
+export function EditButton({
+  onClick,
+  disabled = false,
+  className,
+  size = "sm",
+  variant = "outline",
+  children,
+  ...props
+}: EditButtonProps) {
+  return (
+    <Button
+      onClick={onClick}
+      disabled={disabled}
+      size={size}
+      variant={variant}
+      className={cn(
+        "h-8 px-3 text-muted-foreground hover:text-foreground transition-colors",
+        className
+      )}
+      {...props}
+    >
+      <Edit3 className="h-4 w-4" />
+      <span className="ml-2">{children || "Edit"}</span>
+    </Button>
+  );
+}