Gate realtime audio interruption logic to v2 (#14984)

- thread the realtime version into conversation start and app-server
notifications
- keep playback-aware mic gating and playback interruption behavior on
v2 only, leaving v1 on the legacy path

codex-rs/app-server-protocol/schema/json/ServerNotification.json

@@ -1694,6 +1694,13 @@
       ],
       "type": "object"
     },
+    "RealtimeConversationVersion": {
+      "enum": [
+        "v1",
+        "v2"
+      ],
+      "type": "string"
+    },
     "ReasoningEffort": {
       "description": "See https://platform.openai.com/docs/guides/reasoning?api-mode=responses#get-started-with-reasoning",
       "enum": [
@@ -2857,10 +2864,14 @@
         },
         "threadId": {
           "type": "string"
+        },
+        "version": {
+          "$ref": "#/definitions/RealtimeConversationVersion"
         }
       },
       "required": [
-        "threadId"
+        "threadId",
+        "version"
       ],
       "type": "object"
     },

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

@@ -9719,6 +9719,13 @@
           }
         ]
       },
+      "RealtimeConversationVersion": {
+        "enum": [
+          "v1",
+          "v2"
+        ],
+        "type": "string"
+      },
       "ReasoningEffort": {
         "description": "See https://platform.openai.com/docs/guides/reasoning?api-mode=responses#get-started-with-reasoning",
         "enum": [
@@ -12767,10 +12774,14 @@
           },
           "threadId": {
             "type": "string"
+          },
+          "version": {
+            "$ref": "#/definitions/v2/RealtimeConversationVersion"
           }
         },
         "required": [
-          "threadId"
+          "threadId",
+          "version"
         ],
         "title": "ThreadRealtimeStartedNotification",
         "type": "object"

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

@@ -6507,6 +6507,13 @@
         }
       ]
     },
+    "RealtimeConversationVersion": {
+      "enum": [
+        "v1",
+        "v2"
+      ],
+      "type": "string"
+    },
     "ReasoningEffort": {
       "description": "See https://platform.openai.com/docs/guides/reasoning?api-mode=responses#get-started-with-reasoning",
       "enum": [
@@ -10527,10 +10534,14 @@
         },
         "threadId": {
           "type": "string"
+        },
+        "version": {
+          "$ref": "#/definitions/RealtimeConversationVersion"
         }
       },
       "required": [
-        "threadId"
+        "threadId",
+        "version"
       ],
       "title": "ThreadRealtimeStartedNotification",
       "type": "object"

codex-rs/app-server-protocol/schema/json/v2/ThreadRealtimeStartedNotification.json

@@ -1,5 +1,14 @@
 {
   "$schema": "http://json-schema.org/draft-07/schema#",
+  "definitions": {
+    "RealtimeConversationVersion": {
+      "enum": [
+        "v1",
+        "v2"
+      ],
+      "type": "string"
+    }
+  },
   "description": "EXPERIMENTAL - emitted when thread realtime startup is accepted.",
   "properties": {
     "sessionId": {
@@ -10,10 +19,14 @@
     },
     "threadId": {
       "type": "string"
+    },
+    "version": {
+      "$ref": "#/definitions/RealtimeConversationVersion"
     }
   },
   "required": [
-    "threadId"
+    "threadId",
+    "version"
   ],
   "title": "ThreadRealtimeStartedNotification",
   "type": "object"