🚀 feat: Artifact Editing & Downloads (#5428)

* refactor: expand container

* chore: bump @codesandbox/sandpack-react to latest

* WIP: first pass, show editor

* feat: implement ArtifactCodeEditor and ArtifactTabs components for enhanced artifact management

* refactor: fileKey

* refactor: auto scrolling code editor and add messageId to artifact

* feat: first pass, editing artifact

* feat: first pass, robust artifact replacement

* fix: robust artifact replacement & re-render when expected

* feat: Download Artifacts

* refactor: improve artifact editing UX

* fix: layout shift of new download button

* fix: enhance missing output checks and logging in StreamRunManager

client/src/Providers/ArtifactContext.tsx

@@ -0,0 +1,32 @@
+import { createContext, useContext, ReactNode, useCallback, useRef } from 'react';
+
+type TArtifactContext = {
+  getNextIndex: (skip: boolean) => number;
+  resetCounter: () => void;
+};
+
+export const ArtifactContext = createContext<TArtifactContext>({} as TArtifactContext);
+export const useArtifactContext = () => useContext(ArtifactContext);
+
+export function ArtifactProvider({ children }: { children: ReactNode }) {
+  const counterRef = useRef(0);
+
+  const getNextIndex = useCallback((skip: boolean) => {
+    if (skip) {
+      return counterRef.current;
+    }
+    const nextIndex = counterRef.current;
+    counterRef.current += 1;
+    return nextIndex;
+  }, []);
+
+  const resetCounter = useCallback(() => {
+    counterRef.current = 0;
+  }, []);
+
+  return (
+    <ArtifactContext.Provider value={{ getNextIndex, resetCounter }}>
+      {children}
+    </ArtifactContext.Provider>
+  );
+}