[codex-analytics] add protocol-native turn timestamps

codex-rs/app-server-protocol/schema/json/codex_app_server_protocol.schemas.json

@@ -14364,6 +14364,19 @@
       "TurnCompletedNotification": {
         "$schema": "http://json-schema.org/draft-07/schema#",
         "properties": {
+          "completedAt": {
+            "description": "Unix timestamp (in seconds) when the turn completed.",
+            "format": "int64",
+            "type": "integer"
+          },
+          "durationMs": {
+            "description": "Duration between turn start and completion in milliseconds, if known.",
+            "format": "int64",
+            "type": [
+              "integer",
+              "null"
+            ]
+          },
           "threadId": {
             "type": "string"
           },
@@ -14372,6 +14385,7 @@
           }
         },
         "required": [
+          "completedAt",
           "threadId",
           "turn"
         ],
@@ -14640,6 +14654,11 @@
       "TurnStartedNotification": {
         "$schema": "http://json-schema.org/draft-07/schema#",
         "properties": {
+          "createdAt": {
+            "description": "Unix timestamp (in seconds) when the turn started.",
+            "format": "int64",
+            "type": "integer"
+          },
           "threadId": {
             "type": "string"
           },
@@ -14648,6 +14667,7 @@
           }
         },
         "required": [
+          "createdAt",
           "threadId",
           "turn"
         ],