feat: integrate Radix UI toggle components and replace custom toast implementation with Sonner

- Added @radix-ui/react-toggle and @radix-ui/react-toggle-group to package dependencies.
- Implemented ToggleGroup and Toggle components for improved UI interaction.
- Replaced custom toast notifications with Sonner for better user feedback.
- Updated CanvasPage and ProjectsPage to utilize new toast notifications.
- Removed obsolete toast context and provider.
- Enhanced ProjectsPage with a toggle view for project display (cards/table).

frontend/src/components/ui/toggle.tsx

@@ -0,0 +1,43 @@
+import * as React from "react"
+import * as TogglePrimitive from "@radix-ui/react-toggle"
+import { cva, type VariantProps } from "class-variance-authority"
+
+import { cn } from "@/lib/utils"
+
+const toggleVariants = cva(
+  "inline-flex items-center justify-center gap-2 rounded-md text-sm font-medium transition-colors hover:bg-muted hover:text-muted-foreground focus-visible:outline-none focus-visible:ring-1 focus-visible:ring-ring disabled:pointer-events-none disabled:opacity-50 data-[state=on]:bg-accent data-[state=on]:text-accent-foreground [&_svg]:pointer-events-none [&_svg]:size-4 [&_svg]:shrink-0",
+  {
+    variants: {
+      variant: {
+        default: "bg-transparent",
+        outline:
+          "border border-input bg-transparent shadow-sm hover:bg-accent hover:text-accent-foreground",
+      },
+      size: {
+        default: "h-9 px-2 min-w-9",
+        sm: "h-8 px-1.5 min-w-8",
+        lg: "h-10 px-2.5 min-w-10",
+      },
+    },
+    defaultVariants: {
+      variant: "default",
+      size: "default",
+    },
+  }
+)
+
+const Toggle = React.forwardRef<
+  React.ElementRef<typeof TogglePrimitive.Root>,
+  React.ComponentPropsWithoutRef<typeof TogglePrimitive.Root> &
+    VariantProps<typeof toggleVariants>
+>(({ className, variant, size, ...props }, ref) => (
+  <TogglePrimitive.Root
+    ref={ref}
+    className={cn(toggleVariants({ variant, size, className }))}
+    {...props}
+  />
+))
+
+Toggle.displayName = TogglePrimitive.Root.displayName
+
+export { Toggle, toggleVariants }