feat(checkpoint): expose mainnet Etherscan links on Chain 138 tx attestation.

Resolve etherscanLinks from batch metadata and optional mainnet log scans; serve a fast local-batch attestation path for the explorer CT.

Co-authored-by: Cursor <cursoragent@cursor.com>

services/token-aggregation/src/api/server.ts

@@ -123,6 +123,10 @@ export class ApiServer {
       this.app.use('/static', express.static(publicPath, staticOpts));
       this.app.use('/omnl/static', express.static(publicPath, staticOpts));
       this.app.use('/reserve/static', express.static(publicPath, staticOpts));
+      this.app.use(
+        '/chain138-attestation',
+        express.static(path.join(publicPath, 'chain138-attestation'), staticOpts)
+      );
     }
   }