feat: 大屏后端（FastAPI+MQTT+sim_engine）

- REST :10085 / MQTT 控制 / SSE 回退 / AI+语音
- 数据源规划：接核心服务端 + 算力引擎真实数据

backend/vendor/s2s-cloud/archive/README.md

@@ -0,0 +1,11 @@
+# Archived Models
+
+This directory stores sunset model implementations that are kept in-repo but are no longer wired into `s2s_pipeline.py`.
+
+- STT: `moonshine` -> `archive/STT/moonshine_handler.py`
+- TTS: `parler` -> `archive/TTS/parler_handler.py`
+- TTS: `melo` -> `archive/TTS/melo_handler.py`
+- Legacy args: `archive/arguments_classes/parler_tts_arguments.py`
+- Legacy args: `archive/arguments_classes/melo_tts_arguments.py`
+
+These models are also removed from default requirements. If you want to run them manually, install their dependencies separately.