fix: contain result observer rejections and correct bundle attribution

packages/core/tools/src/index.ts

@@ -958,14 +958,18 @@ export class ToolRegistry extends Service {
     // Freeze the remaining mutable signal slot before observers receive the
     // shared WeakMap-keyable execution object.
     Object.freeze(exec)
+    const reportFailure = (error: unknown): void => {
+      this.ctx.logger.warn(`tool "${exec.name}" (${exec.callId}): tools/result observer failed: ${errorMessage(error)}`)
+    }
     const callbacks = this.ctx.events.dispatch('emit', [
       scopeTarget(this, exec.agent), 'tools/result', exec, result,
     ])
     for (const callback of callbacks) {
       try {
-        callback(exec, result)
+        const returned: unknown = callback(exec, result)
+        void Promise.resolve(returned).catch(reportFailure)
       } catch (error: unknown) {
-        this.ctx.logger.warn(`tool "${exec.name}" (${exec.callId}): tools/result observer failed: ${errorMessage(error)}`)
+        reportFailure(error)
       }
     }
   }