feat: enhance canvas and layout components with new features and improvements

- Added remote image patterns to the Next.js configuration for enhanced image handling.
- Updated TypeScript configuration to exclude the 'implement' directory.
- Refactored layout component to fetch initial authentication token and pass it to Providers.
- Replaced CanvasToolbar with CanvasSidebar for improved UI layout and functionality.
- Enhanced Canvas component with new drag-and-drop file upload capabilities and batch node movement.
- Updated various node components to support new status handling and improved user interactions.
- Added debounced saving for note and prompt nodes to optimize performance.

hooks/use-debounced-callback.ts

@@ -0,0 +1,37 @@
+import { useRef, useCallback, useEffect } from "react";
+
+/**
+ * Debounced callback — ruft `callback` erst auf, wenn `delay` ms
+ * ohne erneuten Aufruf vergangen sind. Perfekt für Auto-Save.
+ */
+export function useDebouncedCallback<Args extends unknown[]>(
+  callback: (...args: Args) => void,
+  delay: number,
+): (...args: Args) => void {
+  const timeoutRef = useRef<ReturnType<typeof setTimeout> | null>(null);
+  const callbackRef = useRef(callback);
+
+  // Callback-Ref aktuell halten ohne neu zu rendern
+  useEffect(() => {
+    callbackRef.current = callback;
+  }, [callback]);
+
+  // Cleanup bei Unmount
+  useEffect(() => {
+    return () => {
+      if (timeoutRef.current) clearTimeout(timeoutRef.current);
+    };
+  }, []);
+
+  const debouncedFn = useCallback(
+    (...args: Args) => {
+      if (timeoutRef.current) clearTimeout(timeoutRef.current);
+      timeoutRef.current = setTimeout(() => {
+        callbackRef.current(...args);
+      }, delay);
+    },
+    [delay],
+  );
+
+  return debouncedFn;
+}