fix: omit display-name-only diagnostics from embedded worker creation

Keep requested names as display names without emitting an informational diagnostic for ordinary creation. Preserve execution failure diagnostics and cover named success and failure paths.

crates/workspace-server/src/hosts.rs

@@ -3156,13 +3156,6 @@ impl WorkspaceWorkerRuntime for EmbeddedWorkerRuntime {
                 diagnostics,
             };
         }
-        if request.requested_worker_name.is_some() {
-            diagnostics.push(diagnostic(
-                "embedded_worker_name_display_only",
-                HostDiagnosticSeverity::Info,
-                "requested_worker_name is used only as display_name; Worker identity is allocated by Workspace authority".to_string(),
-            ));
-        }
         if matches!(request.acceptance, WorkerSpawnAcceptanceRequirement::RunAccepted { expected_segments } if expected_segments > 0)
         {
             diagnostics.push(diagnostic(
@@ -8421,9 +8414,12 @@ mod tests {
             Arc::new(FailingSpawnBackend),
         )
         .expect("test backend should connect");
-        let spawned = runtime.spawn_worker(test_create_binding(), embedded_spawn_request());
+        let mut request = embedded_spawn_request();
+        request.requested_worker_name = Some("friendly-name".into());
+        let spawned = runtime.spawn_worker(test_create_binding(), request);
         assert_eq!(spawned.state, InternalWorkerOperationState::Rejected);
         assert!(spawned.acceptance_evidence.is_empty());
+        assert_eq!(spawned.diagnostics.len(), 1);
         assert!(spawned.diagnostics.iter().any(|diagnostic| {
             diagnostic.code == "embedded_worker_execution_rejected"
                 && diagnostic
@@ -8594,7 +8590,9 @@ mod tests {
                 .iter()
                 .any(|evidence| evidence.kind == "embedded_runtime_backend_internal_projection")
         );
+        assert!(spawned.diagnostics.is_empty());
         let worker = spawned.worker.expect("created embedded worker");
+        assert_eq!(worker.display_name, "friendly-name-is-not-authority");
         assert_eq!(worker.worker.runtime_id, EMBEDDED_RUNTIME_ID);
         assert_eq!(worker.workspace.visibility, "backend_internal");
         assert_eq!(worker.workspace.identity, "runtime_registry_worker");