Initial commit: clean project structure

- Backend: FastAPI + SQLAlchemy + Celery (Python 3.11+)
- Frontend: Vue 3 + TypeScript + Pinia + Tailwind
- Admin Frontend: separate Vue 3 app for management
- Docker Compose: 9 services orchestration
- Specs: design prototypes, memory system PRD, product roadmap

Cleanup performed:
- Removed temporary debug scripts from backend root
- Removed deprecated admin_app.py (embedded UI)
- Removed duplicate docs from admin-frontend
- Updated .gitignore for Vite cache and egg-info

backend/app/services/adapters/tts/edge_tts.py

@@ -0,0 +1,66 @@
+"""EdgeTTS 免费语音生成适配器。"""
+
+import time
+
+import edge_tts
+
+from app.core.logging import get_logger
+from app.services.adapters.base import BaseAdapter
+from app.services.adapters.registry import AdapterRegistry
+
+logger = get_logger(__name__)
+
+# 默认中文女声 (晓晓)
+DEFAULT_VOICE = "zh-CN-XiaoxiaoNeural"
+
+
+@AdapterRegistry.register("tts", "edge_tts")
+class EdgeTTSAdapter(BaseAdapter[bytes]):
+    """EdgeTTS 语音生成适配器 (Free)。
+
+    不需要 API Key。
+    """
+
+    adapter_type = "tts"
+    adapter_name = "edge_tts"
+
+    async def execute(self, text: str, **kwargs) -> bytes:
+        """生成语音。"""
+        # 支持动态指定音色
+        voice = kwargs.get("voice") or self.config.model or DEFAULT_VOICE
+
+        start_time = time.time()
+        logger.info("edge_tts_generate_start", text_length=len(text), voice=voice)
+
+        # EdgeTTS 只能输出到文件，我们需要用临时文件周转一下
+        # 或者直接 capture stream (communicate) 但 edge-tts 库主要面向文件
+
+        # 优化: 使用 communicate 直接获取 bytes，无需磁盘IO
+        communicate = edge_tts.Communicate(text, voice)
+
+        audio_data = b""
+        async for chunk in communicate.stream():
+            if chunk["type"] == "audio":
+                audio_data += chunk["data"]
+
+        elapsed = time.time() - start_time
+        logger.info(
+            "edge_tts_generate_success",
+            elapsed_seconds=round(elapsed, 2),
+            audio_size_bytes=len(audio_data),
+        )
+
+        return audio_data
+
+    async def health_check(self) -> bool:
+        """检查 EdgeTTS 是否可用 (网络连通性)。"""
+        try:
+            # 简单生成一个词
+            await self.execute("Hi")
+            return True
+        except Exception:
+            return False
+
+    @property
+    def estimated_cost(self) -> float:
+        return 0.0  # Free!