feat(phase1): core/ 基础设施迁移，旧路径改垫片

- core/: database/redis_client/jwt/password/response/exceptions/security/logger/deps/middleware/app
- create_app 迁移到 core/app.py，中间件注册顺序与异常处理器原样保留
- extensions/ utils/ apps/ 旧文件全部改为 re-export 垫片，import 路径保持兼容
- 新增 core 单元测试（jwt/password/response/request 共 12 个）

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

core/exceptions.py

@@ -0,0 +1,27 @@
+# +======================================================================
+# | DjangoAdmin 企业数字化开发平台 [ 赋能开发者，助力企业发展 ]
+# +----------------------------------------------------------------------
+# | Copyright (c) 2021-2026 一米阳光团队 版权所有
+# | 开源协议: Apache-2.0
+# +======================================================================
+# 由 extensions/exception.py 迁移而来。
+
+"""统一异常类型：登录认证异常 + 业务异常。"""
+
+
+class AuthorizationException(Exception):
+    """登录认证异常，由 login_required 中间件抛出。"""
+
+    def __init__(self, code: int, msg: str):
+        super().__init__(msg)
+        self.code = code
+        self.msg = msg
+
+
+class BusinessException(Exception):
+    """业务异常，业务代码可主动抛出。"""
+
+    def __init__(self, code: int = 1, msg: str = ""):
+        super().__init__(msg)
+        self.code = code
+        self.msg = msg