feat: FastAPI skeleton with config, database, health endpoint

Co-Authored-By: Claude <noreply@anthropic.com>

backend/app/config.py

@@ -0,0 +1,18 @@
+"""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()