Fix block rename error handling and type annotation

- Move stopBlockRename() to only execute after successful RPC
- Keep rename input open on error so user can retry
- Add explicit type cast for followTermMenuDataAtom to fix type inference

Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>

Author: cowhen

frontend/app/block/blockframe-header.tsx

@@ -113,10 +113,10 @@ const HeaderTextElems = React.memo(({ viewModel, blockId, preview, error }: Head
                     oref: WOS.makeORef("block", blockId),
                     meta: { "frame:title": val },
                 });
+                stopBlockRename();
             } catch (error) {
                 console.error("Failed to save block rename:", error);
             }
-            stopBlockRename();
         },
         [blockId, waveEnv]
     );

frontend/app/view/preview/preview-model.tsx

@@ -514,7 +514,7 @@ export class PreviewModel implements ViewModel {
         this.followTermBidirAtom = atom<boolean>((get) => {
             return (get(this.blockAtom)?.meta?.["preview:followterm:bidir"] as boolean) ?? false;
         });
-        this.followTermMenuDataAtom = atom(null);
+        this.followTermMenuDataAtom = atom(null) as PrimitiveAtom<{ pos: any; terms: any; currentFollowId: any; bidir: any } | null>;
     }
 
     showFollowTermMenu(e: React.MouseEvent<any>) {