[codex-analytics] add protocol-native turn timestamps

codex-rs/app-server-protocol/schema/json/codex_app_server_protocol.v2.schemas.json

@@ -12219,6 +12219,19 @@
     "TurnCompletedNotification": {
       "$schema": "http://json-schema.org/draft-07/schema#",
       "properties": {
+        "completedAt": {
+          "description": "Unix timestamp (in seconds) when the turn completed.",
+          "format": "int64",
+          "type": "integer"
+        },
+        "durationMs": {
+          "description": "Duration between turn start and completion in milliseconds, if known.",
+          "format": "int64",
+          "type": [
+            "integer",
+            "null"
+          ]
+        },
         "threadId": {
           "type": "string"
         },
@@ -12227,6 +12240,7 @@
         }
       },
       "required": [
+        "completedAt",
         "threadId",
         "turn"
       ],
@@ -12495,6 +12509,11 @@
     "TurnStartedNotification": {
       "$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"
         },
@@ -12503,6 +12522,7 @@
         }
       },
       "required": [
+        "createdAt",
         "threadId",
         "turn"
       ],