Implement secure cloud sandboxes with E2B (#35)

* chore: rename utils.ts to fileoperations.ts

* feat: replace node-pty with E2B sandboxes

* added debounced function in the editor

* fix: move socket connection to useRef

* fix: wait until terminals are killed to close the container

* fix: ensure container remains open until all owner connections are closed

* fix: sync files to container instead of local file system

* fix: set project file permissions so that they belong to the terminal user

* fix: use the container URL for the preview panel

* fix: count only the current user's sandboxes towards the limit

* fix: remove hardcoded reference to localhost

* fix: add error handling to the backend

* docs: add information about E2B

---------

Co-authored-by: Akhilesh Rangani <akhileshrangani4@gmail.com>

frontend/lib/utils.ts

@@ -61,3 +61,13 @@ export function addNew(
     ])
   }
 }
+
+export function debounce<T extends (...args: any[]) => void>(func: T, wait: number): T {
+  let timeout: NodeJS.Timeout | null = null;
+  return function (...args: Parameters<T>) {
+      if (timeout) {
+          clearTimeout(timeout);
+      }
+      timeout = setTimeout(() => func(...args), wait);
+  } as T;
+}