feat(executor): 重构用例加载与执行逻辑，支持参数化变量优先级

- 引入 CaseEntity 包装器，实现数据模型与执行上下文解耦。
 - 移除加载阶段的 deepcopy，优化大规模参数化用例的内存占用。
 - 实现 perform 阶段的局部变量注入，确保参数化数据优先级高于全局缓存。

test_cases/answer/test_1_status.yaml

@@ -12,6 +12,9 @@ request:
     User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/131.0.0.0 Safari/537.36 Edg/131.0.0.0
     Referer: http://119.91.19.171:40065/users/login
     Accept-Encoding: gzip, deflate
+  json_body:
+    username: "${username}"
+    password: "${password}"
 extract: # 提取变量
   msg:
     - "json"
@@ -19,20 +22,21 @@ extract: # 提取变量
     - 0
 
 validate:
-  - check: status_code    # 检查的对象（或是变量名）
-    assert: equals        # 断言方法
-    expect: 200           # 期望值
-    msg: "校验接口状态码"   # 描述（可选）
+  - check: status_code
+    assert: ${status_assert}        # <--- 动态断言方法
+    expect: ${status_expect}        # <--- 动态期望值
+    msg: "校验接口状态码"
 
-  - check: $.msg
-    assert: contains
-    expect: "Success"
+  - check: message
+    assert: ${msg_assert}           # <--- 动态断言方法
+    expect: ${msg_expect}           # <--- 动态期望值
     msg: "检查返回消息"
 
 parametrize: # 数据驱动测试
-  - [ "title","username","password","msg" ] # 变量名
-  - [ "测试1","user1","pass1","200" ] # 变量值
-  - [ "测试2","user2","pass2","300" ] # 变量值
-  - [ "测试3","user3","pass3","200" ] # 变量值
-  - [ "测试4","user4","pass4","200" ] # 变量值
-  - [ "测试5","user5","pass5","200" ] # 变量值
+  # 定义列名，包括了断言方法和期望值
+  - [ "title", "username", "password", "status_assert", "status_expect", "msg_assert", "msg_expect" ]
+  # 定义每一行的数据，现在可以为每次运行指定不同的断言逻辑
+  - [ "场景1: 成功-状态码相等-消息包含Success", "user1", "pass1", "equals", 200, "contains", "Success" ]
+  - [ "场景2: 失败-状态码不相等-消息不包含Error", "user2", "pass2", "not_equals", 200, "not_contains", "Error" ]
+  - [ "场景3: 成功-状态码大于199-消息相等", "user3", "pass3", "greater_than", 199, "equals", "Success" ]
+  - [ "场景4: 失败-状态码小于500-消息为空", "user4", "pass4", "less_than", 500, "is_empty", "" ]