fix(trigger): require names for trigger creation

tests/command/test_trigger_command.py

@@ -45,5 +45,33 @@ async def test_trigger_command_creates_session_bound_local_trigger(tmp_path: Pat
     assert f"nanobot trigger {trigger.id} \"message\"" in response.content
 
 
+@pytest.mark.asyncio
+async def test_trigger_command_without_name_returns_usage_only(tmp_path: Path) -> None:
+    router = CommandRouter()
+    register_builtin_commands(router)
+    store = ExternalTriggerStore(tmp_path)
+    loop = SimpleNamespace(workspace=tmp_path, external_trigger_store=store)
+    msg = InboundMessage(
+        channel="websocket",
+        sender_id="user",
+        chat_id="chat-1",
+        content="/trigger@nanobot_bot",
+        metadata={"webui": True},
+    )
+    ctx = CommandContext(
+        msg=msg,
+        session=None,
+        key="websocket:chat-1",
+        raw="/trigger@nanobot_bot",
+        loop=loop,
+    )
+
+    response = await router.dispatch(ctx)
+
+    assert response is not None
+    assert "Usage: /trigger <name>" in response.content
+    assert store.list_for_session("websocket:chat-1") == []
+
+
 def test_trigger_command_is_in_help_text() -> None:
-    assert "/trigger [name]" in build_help_text()
+    assert "/trigger <name>" in build_help_text()