fix: satisfy BlobPart under @types/node 26 in pythinker-files providers

Same assertion dev already carries; upstream builds against @types/node 22.

Author: elkaix

packages/agent-core-v2/src/kosong/provider/providers/pythinker/pythinker-files.ts

@@ -77,7 +77,10 @@ export class PythinkerFiles {
       }
       const filename = input.filename ?? guessFilename(input.mimeType);
       const bytes = input.data instanceof Uint8Array ? input.data : new Uint8Array(input.data);
-      const blob = new Blob([bytes], { type: input.mimeType });
+      // `BlobPart` requires a non-shared backing buffer under @types/node 26;
+      // the assertion is safe because these bytes never come from a
+      // SharedArrayBuffer.
+      const blob = new Blob([bytes as Uint8Array<ArrayBuffer>], { type: input.mimeType });
       file = new File([blob], filename, { type: input.mimeType });
     }
 

packages/kosong/src/providers/pythinker-files.ts

@@ -114,7 +114,10 @@ export class PythinkerFiles {
       // `Blob` and `File` are available as globals in Node 20+. The cast via
       // `Uint8Array` satisfies `BlobPart` in both Node and DOM lib contexts.
       const bytes = input.data instanceof Uint8Array ? input.data : new Uint8Array(input.data);
-      const blob = new Blob([bytes], { type: input.mimeType });
+      // `BlobPart` requires a non-shared backing buffer under @types/node 26;
+      // the assertion is safe because these bytes never come from a
+      // SharedArrayBuffer.
+      const blob = new Blob([bytes as Uint8Array<ArrayBuffer>], { type: input.mimeType });
       file = new File([blob], filename, { type: input.mimeType });
     }