fix: flatten React Router structure — no nested Routes, each page is a top-level route

docs/superpowers/plans/task-0.3-spec.md

@@ -0,0 +1,91 @@
+请创建以下 3 个文件。backend 目录已存在，但 backend/app/ 需要新建。
+
+## 文件 1: backend/app/__init__.py
+空文件。
+
+## 文件 2: backend/app/config.py
+```python
+"""应用配置 — 从环境变量 / .env 读取。"""
+from pydantic_settings import BaseSettings
+
+
+class Settings(BaseSettings):
+    database_url: str = "postgresql+asyncpg://hive_admin:changeme@localhost:5432/hive_manage_v3"
+    jwt_secret: str = "change-me"
+    jwt_algorithm: str = "HS256"
+    jwt_expire_minutes: int = 1440
+    hermes_cli_path: str = "/home/enzo/.local/bin/hermes"
+    hermes_profiles_root: str = "/home/enzo/.hermes/profiles"
+    admin_email: str = "admin@zhiwei.local"
+    admin_password: str = "admin123"
+
+    model_config = {"env_file": ".env"}
+
+
+settings = Settings()
+```
+
+## 文件 3: backend/app/database.py
+```python
+"""异步 SQLAlchemy 引擎 + session 工厂。"""
+from sqlalchemy.ext.asyncio import create_async_engine, async_sessionmaker, AsyncSession
+from sqlalchemy.orm import DeclarativeBase
+
+from app.config import settings
+
+engine = create_async_engine(settings.database_url, echo=False)
+async_session = async_sessionmaker(engine, class_=AsyncSession, expire_on_commit=False)
+
+
+class Base(DeclarativeBase):
+    pass
+
+
+async def get_db() -> AsyncSession:
+    async with async_session() as session:
+        yield session
+```
+
+## 文件 4: backend/app/main.py
+```python
+"""FastAPI 应用入口。"""
+from contextlib import asynccontextmanager
+from fastapi import FastAPI
+from fastapi.middleware.cors import CORSMiddleware
+
+from app.database import engine, Base
+
+
+@asynccontextmanager
+async def lifespan(app: FastAPI):
+    async with engine.begin() as conn:
+        await conn.run_sync(Base.metadata.create_all)
+    yield
+    await engine.dispose()
+
+
+app = FastAPI(
+    title="Hive Manage v3",
+    version="0.1.0",
+    lifespan=lifespan,
+)
+
+app.add_middleware(
+    CORSMiddleware,
+    allow_origins=["*"],
+    allow_credentials=True,
+    allow_methods=["*"],
+    allow_headers=["*"],
+)
+
+
+@app.get("/api/v1/health")
+async def health_check():
+    return {"status": "ok"}
+```
+
+创建完成后，执行以下验证：
+1. `cat` 检查每个文件内容
+2. `cd backend && pip install -e ".[dev]"` 安装依赖
+3. `cd backend && python -c "from app.main import app; print('FastAPI app created OK')"` 验证导入
+4. git add + git commit -m "feat: FastAPI skeleton with config, database, health endpoint"