Add SVG icons for code and preview, implement sandbox functionality in interaction panel

- Added Code.svg and Preview.svg icons to the public/icons directory.
- Refactored chat.tsx to remove duplicate import of observer from mobx-react-lite.
- Enhanced interaction-panel.tsx to include a new Sandbox component with code and preview toggling functionality using Sandpack.
- Updated styles.css to include custom styles for the new sandbox layout and file explorer. (add sandpack)

src/styles.css

@@ -158,4 +158,17 @@ input:focus {
   
   .toast-progress-animation {
     animation: toast-progress 5s linear forwards;
+  }
+
+  .custom-wrapper { 
+    height: 100%;
+  }
+
+  .custom-layout {
+    height: 100%;
+  }
+
+  .custom-file-explorer .custom-file-explorer-list {
+    height: 100%;
+    overflow: visible;
   }