fix: improve getBlock() guards with proper state cleanup and async safety

- SideMenu: hide menu and clear hoveredBlock when getBlock returns
  undefined, preventing stale visible state
- EmbedTab: re-check block existence before each updateBlock call
- UploadTab: re-check block existence after async upload resolves
- TableHandles: use typed local variable instead of as any cast

Author: nperez0111

packages/core/src/extensions/SideMenu/SideMenu.ts

@@ -245,6 +245,11 @@ export class SideMenuView<
         this.hoveredBlock!.getAttribute("data-id")!,
       );
       if (!sideMenuBlock) {
+        if (this.state?.show) {
+          this.state.show = false;
+          this.hoveredBlock = undefined;
+          this.emitUpdate(this.state);
+        }
         return;
       }
       this.state = {

packages/core/src/extensions/TableHandles/TableHandles.ts

@@ -533,10 +533,10 @@ export class TableHandlesView implements PluginView {
     }
 
     // Hide handles if the table block has been removed.
-    this.state.block = this.editor.getBlock(this.state.block.id) as any;
+    const refreshedBlock = this.editor.getBlock(this.state.block.id);
     if (
-      !this.state.block ||
-      this.state.block.type !== "table" ||
+      !refreshedBlock ||
+      refreshedBlock.type !== "table" ||
       // when collaborating, the table element might be replaced and out of date
       // because yjs replaces the element when for example you change the color via the side menu
       !this.tableElement?.isConnected
@@ -548,6 +548,7 @@ export class TableHandlesView implements PluginView {
 
       return;
     }
+    this.state.block = refreshedBlock as typeof this.state.block;
 
     const { height: rowCount, width: colCount } = getDimensionsOfTable(
       this.state.block,

packages/react/src/components/FilePanel/DefaultTabs/EmbedTab.tsx

@@ -41,6 +41,9 @@ export const EmbedTab = <
     (event: KeyboardEvent) => {
       if (event.key === "Enter" && !event.nativeEvent.isComposing) {
         event.preventDefault();
+        if (!editor.getBlock(props.blockId)) {
+          return;
+        }
         editor.updateBlock(props.blockId, {
           props: {
             name: filenameFromURL(currentURL),
@@ -53,6 +56,9 @@ export const EmbedTab = <
   );
 
   const handleURLClick = useCallback(() => {
+    if (!editor.getBlock(props.blockId)) {
+      return;
+    }
     editor.updateBlock(props.blockId, {
       props: {
         name: filenameFromURL(currentURL),

packages/react/src/components/FilePanel/DefaultTabs/UploadTab.tsx

@@ -53,6 +53,9 @@ export const UploadTab = <
         if (editor.uploadFile !== undefined) {
           try {
             let updateData = await editor.uploadFile(file, props.blockId);
+            if (!editor.getBlock(props.blockId)) {
+              return;
+            }
             if (typeof updateData === "string") {
               // received a url
               updateData = {