fix(everything): correct blob resource mimeType

The blobResource() factory in src/everything/resources/templates.ts
returned mimeType "text/plain" for what is, by definition, a base64
blob. The registered Dynamic Blob Resource template at the bottom of
the same file already declared "application/octet-stream", so the
factory contradicted its own template metadata.

Downstream, get-resource-links.ts:74-79 branches on this mimeType to
label resources, so every blob resource_link was being described as
"plaintext resource".

Update the factory to return "application/octet-stream" and the
matching test assertion. No behaviour change beyond the mimeType
itself and the now-correct downstream label.

Author: aicayzer

src/everything/__tests__/resources.test.ts

@@ -83,7 +83,7 @@ describe('Resource Templates', () => {
       const resource = blobResource(uri, 1);
 
       expect(resource.uri).toBe(uri.toString());
-      expect(resource.mimeType).toBe('text/plain');
+      expect(resource.mimeType).toBe('application/octet-stream');
       expect(resource.blob).toBeDefined();
     });
 

src/everything/resources/templates.ts

@@ -105,7 +105,7 @@ export const blobResource = (uri: URL, resourceId: number) => {
   ).toString("base64");
   return {
     uri: uri.toString(),
-    mimeType: "text/plain",
+    mimeType: "application/octet-stream",
     blob: resourceText,
   };
 };