fix: query-do executeLanceWholeFile inverted fragmentLoad return code check

fragmentLoad returns 0 on success (matching loadFragment wrapper at
wasm-engine.ts:777), but executeLanceWholeFile threw on 0 — meaning
valid Lance files without page metadata always failed. Inverted to
!== 0 to match the error-code convention.

Author: teamchong

src/query-do.ts

@@ -894,7 +894,7 @@ export class QueryDO extends DurableObject<Env> {
       .set(new Uint8Array(fileData));
 
     const loadResult = this.wasmEngine.exports.fragmentLoad(dataPtr, fileData.byteLength);
-    if (loadResult === 0) throw new QueryModeError("INVALID_FORMAT", `Failed to load Lance fragment (invalid file?)`);
+    if (loadResult !== 0) throw new QueryModeError("INVALID_FORMAT", `Failed to load Lance fragment (invalid file?)`);
 
     // Parse Lance v2 column metadata using shared parser
     const dataset = this.datasetCache.get(query.table);