test(pi): hold packaged rpc confirmation past timeout

electron/coding-runtime/pi/rpc-client.ts

@@ -78,6 +78,7 @@ export class PiRpcClient {
   private readonly pending = new Map<string, PendingRequest>();
   private readonly retiredIds = new Set<string>();
   private readonly listeners = new Set<(event: PiRpcEvent) => void>();
+  private readonly proofResponseDelays = new Map<string, number>();
   private sequence = 0;
   private invalidated: PiProcessError | null = null;
 
@@ -111,6 +112,13 @@ export class PiRpcClient {
     return () => this.listeners.delete(listener);
   }
 
+  delayNextResponseForProof(commandType: string, delayMs: number): void {
+    if (!commandType || !Number.isSafeInteger(delayMs) || delayMs <= 0) {
+      throw new Error('Proof response delay requires a command type and positive safe delay');
+    }
+    this.proofResponseDelays.set(commandType, delayMs);
+  }
+
   async request<T = unknown>(
     command: PiRpcCommand,
     options: PiRpcRequestOptions = {},
@@ -161,6 +169,22 @@ export class PiRpcClient {
       if (!pending) {
         throw new PiProcessError('PI_RPC_PROTOCOL_ERROR', `Pi RPC response used unknown id ${value.id}`);
       }
+      const proofDelayMs = this.proofResponseDelays.get(pending.commandType);
+      if (proofDelayMs !== undefined) {
+        this.proofResponseDelays.delete(pending.commandType);
+        setTimeout(() => {
+          try {
+            this.accept(value);
+          } catch (error) {
+            try {
+              this.onEventListenerError?.(error);
+            } catch {
+              // Proof diagnostics must not affect transport state.
+            }
+          }
+        }, proofDelayMs);
+        return;
+      }
       pending.cancel();
       this.pending.delete(value.id);
       if (value.success) {