Show persistent timestamps for operation and teacher messages

electron/coding-runtime/pi/event-projector.ts

@@ -1,3 +1,4 @@
+import { messageTimestamp } from '../../../shared/message-timestamp';
 import type {
   ConversationContentBlock,
   ConversationMessageNode,
@@ -529,6 +530,7 @@ export class PiEventProjector {
               ? { clientRequestId: optimistic.clientRequestId }
               : {}),
             role: 'user',
+            timestamp: messageTimestamp(message.timestamp) ?? optimistic?.timestamp ?? this.now(),
             status: 'complete',
             blocks: await liveContentBlocks(
               id,
@@ -723,6 +725,8 @@ export class PiEventProjector {
           kind: 'message',
           id,
           role: 'assistant',
+          // Live observation; settlement hydration replaces it with Pi's durable entry time.
+          timestamp: this.now(),
           status: message.stopReason === 'aborted'
             ? 'aborted'
             : message.stopReason === 'error' ? 'error' : 'complete',