fix: prevent mixed-version pushy feedback

Assistant: codex
Assistant-Model: gpt-5.6-sol
Assistant-Session: 01a03397-4d51-7fd1-8ff2-946eb22ea2bc

tests/test_protocol.py

@@ -1,7 +1,7 @@
 import asyncio
 import json
 
-from tamq.service import Service
+from tamq.service import PUSHY_FRAMING_CAPABILITY, Service
 from tamq.store import Store
 
 
@@ -19,3 +19,24 @@ def test_incompatible_protocol_rejected(tmp_path):
         finally:
             server.close(); await server.wait_closed(); service.close()
     asyncio.run(run())
+
+
+def test_ping_advertises_non_routable_pushy_framing(tmp_path):
+    async def run():
+        path = tmp_path / "tamq.sock"
+        service = Service(path, Store(tmp_path / "queue.sqlite3"))
+        server = await asyncio.start_unix_server(service.handle, path=str(path))
+        try:
+            reader, writer = await asyncio.open_unix_connection(str(path))
+            writer.write(b'{"op":"ping"}\n')
+            await writer.drain()
+            response = json.loads(await reader.readline())
+            assert PUSHY_FRAMING_CAPABILITY in response["capabilities"]
+            writer.close()
+            await writer.wait_closed()
+        finally:
+            server.close()
+            await server.wait_closed()
+            service.close()
+
+    asyncio.run(run())