Show persistent timestamps for operation and teacher messages

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

@@ -1,3 +1,4 @@
+import { messageTimestamp } from '../../../shared/message-timestamp';
 import type {
   CodingRuntimeErrorCode,
   ConversationContentBlock,
@@ -235,6 +236,10 @@ async function projectEntries(
       id: messageId,
       sourceEntryId: entry.id,
       role: message.role,
+      // Pi appends the entry on message_end; assistant.message.timestamp is its start time.
+      timestamp: message.role === 'user'
+        ? messageTimestamp(message.timestamp) ?? messageTimestamp(entry.timestamp)
+        : messageTimestamp(entry.timestamp),
       status: message.stopReason === 'aborted'
         ? 'aborted'
         : message.stopReason === 'error' ? 'error' : 'complete',