feat(backend): T1.1 认证与权限 — 注册/登录/刷新/获取用户

- 后端：auth 路由（register/login/refresh/me）+ JWT + bcrypt 密码哈希
- 依赖注入：get_current_user + require_role 角色权限校验
- 跨数据库兼容：JSONBType（PG 用 JSONB，SQLite 用 JSON）
- 测试：11 个认证测试 + 4 个健康检查测试 = 15 passed

backend/app/models/tenant.py

@@ -7,10 +7,10 @@ import uuid
 from datetime import datetime, timezone
 
 from sqlalchemy import DateTime, String
-from sqlalchemy.dialects.postgresql import JSONB
 from sqlalchemy.orm import Mapped, mapped_column
 
 from app.core.database import Base
+from app.core.types import JSONBType
 
 
 class Tenant(Base):
@@ -21,7 +21,7 @@ class Tenant(Base):
     id: Mapped[str] = mapped_column(String(36), primary_key=True, default=lambda: str(uuid.uuid4()))
     name: Mapped[str] = mapped_column(String(200), nullable=False, comment="租户名称")
     type: Mapped[str] = mapped_column(String(50), nullable=False, default="vc", comment="租户类型：vc/cvc/gov/holdings")
-    config_json: Mapped[dict | None] = mapped_column(JSONB, nullable=True, comment="租户配置")
+    config_json: Mapped[dict | None] = mapped_column(JSONBType, nullable=True, comment="租户配置")
     created_at: Mapped[datetime] = mapped_column(
         DateTime(timezone=True), default=lambda: datetime.now(timezone.utc)
     )