Drop redundant buffer copies and a dead hook export

The verified-preview path copied every downloaded byte twice for no
gain: fetchBuffer re-allocated each response chunk element-by-element
via Uint8Array.from before collecting it (Electron's net module
delivers fresh Buffers, so retaining them is safe and Buffer.concat
already performs the single final copy), and the metadata checksum
round-tripped the whole buffer through a latin1 string before hashing,
which allocates an up-to-10MB string to produce the digest hashing the
Buffer directly yields.

Also removes the unused useNFTVideoLoop default export: both consumers
import the named hooks and derive the effective global-or-per-video
state themselves, so the wrapper only added surface that could drift
from the real logic.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01FUAhsJYiWuD36Hq4h49gLg

Author: claude

packages/gui/src/electron/api/nftGetMetadata.ts

@@ -20,7 +20,7 @@ export type NftMetadata = Record<string, unknown> & {
 };
 
 function checksum(data: Buffer): string {
-  return crypto.createHash('sha256').update(data.toString('latin1'), 'latin1').digest('hex');
+  return crypto.createHash('sha256').update(data).digest('hex');
 }
 
 function getImageContentType(headers: Headers): string | undefined {

packages/gui/src/electron/utils/fetchBuffer.ts

@@ -102,22 +102,21 @@ export default async function fetchBuffer(
         }
       }
 
-      const chunks: Uint8Array[] = [];
+      const chunks: Buffer[] = [];
       let dataSize = 0;
 
       response.on('data', (chunk: Buffer) => {
         if (settled) {
           return;
         }
 
-        const buffer = Uint8Array.from(chunk);
-        dataSize += buffer.byteLength;
+        dataSize += chunk.byteLength;
         if (maxSize > 0 && dataSize > maxSize) {
           abortWith(new MaxSizeExceededError(response.headers as Headers));
           return;
         }
 
-        chunks.push(buffer);
+        chunks.push(chunk);
       });
 
       response.on('end', () => {

packages/gui/src/hooks/useNFTVideoLoop.tsx

@@ -34,11 +34,6 @@ export function useNFTVideoLoopForNFT(nftId: string): [boolean, (loopVideo: bool
   return [loop, setLoop];
 }
 
-// The effective looping state for one NFT video: the global preference forces
-// looping on when set, but never disables a video's own loop preference.
-export default function useNFTVideoLoop(nftId: string): boolean {
-  const [globalLoop] = useNFTVideoLoopGlobal();
-  const [videoLoop] = useNFTVideoLoopForNFT(nftId);
-
-  return globalLoop || videoLoop;
-}
+// The effective looping state for one NFT video is `global || perVideo`:
+// the global preference forces looping on when set, but never disables a
+// video's own loop preference. Consumers combine the two hooks above.