Refactor project structure and enhance backend integration

- Expanded package inclusion in `pyproject.toml` to support new modules.
- Introduced new `adapters` and `protocol` packages for better organization.
- Added backend adapter implementations for control plane integration.
- Updated main application imports to reflect new package structure.
- Removed deprecated core components and adjusted documentation accordingly.
- Enhanced architecture documentation to clarify the new runtime and integration layers.

engine/providers/factory/__init__.py

@@ -0,0 +1 @@
+"""Provider factories."""

engine/providers/factory/default.py

@@ -0,0 +1,112 @@
+"""Default runtime service factory implementing core extension ports."""
+
+from __future__ import annotations
+
+from typing import Any
+
+from loguru import logger
+
+from runtime.ports import (
+    ASRPort,
+    ASRServiceSpec,
+    LLMPort,
+    LLMServiceSpec,
+    RealtimeServiceFactory,
+    TTSPort,
+    TTSServiceSpec,
+)
+from providers.asr.buffered import BufferedASRService
+from providers.tts.dashscope import DashScopeTTSService
+from providers.llm.openai import MockLLMService, OpenAILLMService
+from providers.asr.openai_compatible import OpenAICompatibleASRService
+from providers.tts.openai_compatible import OpenAICompatibleTTSService
+from providers.tts.mock import MockTTSService
+
+_OPENAI_COMPATIBLE_PROVIDERS = {"openai_compatible", "openai-compatible", "siliconflow"}
+_SUPPORTED_LLM_PROVIDERS = {"openai", *_OPENAI_COMPATIBLE_PROVIDERS}
+
+
+class DefaultRealtimeServiceFactory(RealtimeServiceFactory):
+    """Build concrete runtime services from normalized specs."""
+
+    _DEFAULT_DASHSCOPE_TTS_REALTIME_URL = "wss://dashscope.aliyuncs.com/api-ws/v1/realtime"
+    _DEFAULT_DASHSCOPE_TTS_MODEL = "qwen3-tts-flash-realtime"
+    _DEFAULT_OPENAI_COMPATIBLE_TTS_MODEL = "FunAudioLLM/CosyVoice2-0.5B"
+    _DEFAULT_OPENAI_COMPATIBLE_ASR_MODEL = "FunAudioLLM/SenseVoiceSmall"
+
+    @staticmethod
+    def _normalize_provider(provider: Any) -> str:
+        return str(provider or "").strip().lower()
+
+    @staticmethod
+    def _resolve_dashscope_mode(raw_mode: Any) -> str:
+        mode = str(raw_mode or "commit").strip().lower()
+        if mode in {"commit", "server_commit"}:
+            return mode
+        return "commit"
+
+    def create_llm_service(self, spec: LLMServiceSpec) -> LLMPort:
+        provider = self._normalize_provider(spec.provider)
+        if provider in _SUPPORTED_LLM_PROVIDERS and spec.api_key:
+            return OpenAILLMService(
+                api_key=spec.api_key,
+                base_url=spec.base_url,
+                model=spec.model,
+                system_prompt=spec.system_prompt,
+                knowledge_config=spec.knowledge_config,
+                knowledge_searcher=spec.knowledge_searcher,
+            )
+
+        logger.warning(
+            "LLM provider unsupported or API key missing (provider={}); using mock LLM",
+            provider or "-",
+        )
+        return MockLLMService()
+
+    def create_tts_service(self, spec: TTSServiceSpec) -> TTSPort:
+        provider = self._normalize_provider(spec.provider)
+
+        if provider == "dashscope" and spec.api_key:
+            return DashScopeTTSService(
+                api_key=spec.api_key,
+                api_url=spec.api_url or self._DEFAULT_DASHSCOPE_TTS_REALTIME_URL,
+                voice=spec.voice,
+                model=spec.model or self._DEFAULT_DASHSCOPE_TTS_MODEL,
+                mode=self._resolve_dashscope_mode(spec.mode),
+                sample_rate=spec.sample_rate,
+                speed=spec.speed,
+            )
+
+        if provider in _OPENAI_COMPATIBLE_PROVIDERS and spec.api_key:
+            return OpenAICompatibleTTSService(
+                api_key=spec.api_key,
+                api_url=spec.api_url,
+                voice=spec.voice,
+                model=spec.model or self._DEFAULT_OPENAI_COMPATIBLE_TTS_MODEL,
+                sample_rate=spec.sample_rate,
+                speed=spec.speed,
+            )
+
+        logger.warning(
+            "TTS provider unsupported or API key missing (provider={}); using mock TTS",
+            provider or "-",
+        )
+        return MockTTSService(sample_rate=spec.sample_rate)
+
+    def create_asr_service(self, spec: ASRServiceSpec) -> ASRPort:
+        provider = self._normalize_provider(spec.provider)
+
+        if provider in _OPENAI_COMPATIBLE_PROVIDERS and spec.api_key:
+            return OpenAICompatibleASRService(
+                api_key=spec.api_key,
+                api_url=spec.api_url,
+                model=spec.model or self._DEFAULT_OPENAI_COMPATIBLE_ASR_MODEL,
+                sample_rate=spec.sample_rate,
+                language=spec.language,
+                interim_interval_ms=spec.interim_interval_ms,
+                min_audio_for_interim_ms=spec.min_audio_for_interim_ms,
+                on_transcript=spec.on_transcript,
+            )
+
+        logger.info("Using buffered ASR service (provider={})", provider or "-")
+        return BufferedASRService(sample_rate=spec.sample_rate, language=spec.language)