fix(core): throw AggregateError after Promise.allSettled to preserve caller failure detection

Keep Promise.allSettled for resilience (all providers get a chance to flush),
but throw AggregateError if any failed so callers can still detect failures.

Co-authored-by: Eric Allam <ericallam@users.noreply.github.com>

Author: github-actions[bot]

packages/core/src/v3/otel/tracingSDK.ts

@@ -375,11 +375,16 @@ export class TracingSDK {
       this._meterProvider.forceFlush(),
     ]);
     const providerNames = ["trace", "log", "meter"] as const;
+    const errors: Error[] = [];
     results.forEach((result, index) => {
       if (result.status === "rejected") {
         console.error(`Failed to flush ${providerNames[index]} provider:`, result.reason);
+        errors.push(result.reason instanceof Error ? result.reason : new Error(String(result.reason)));
       }
     });
+    if (errors.length > 0) {
+      throw new AggregateError(errors, "One or more providers failed to flush");
+    }
   }
 
   public async shutdown() {
@@ -389,11 +394,16 @@ export class TracingSDK {
       this._meterProvider.shutdown(),
     ]);
     const providerNames = ["trace", "log", "meter"] as const;
+    const errors: Error[] = [];
     results.forEach((result, index) => {
       if (result.status === "rejected") {
         console.error(`Failed to shutdown ${providerNames[index]} provider:`, result.reason);
+        errors.push(result.reason instanceof Error ? result.reason : new Error(String(result.reason)));
       }
     });
+    if (errors.length > 0) {
+      throw new AggregateError(errors, "One or more providers failed to shutdown");
+    }
   }
 }