fix(Translator): 类体 CDefine 预扫描扩展 + CDefine 类型修复（i32）

- GenerateLlvmDirect 预扫描扩展到类体 AnnAssign，注册类体 CDefine 常量
  （方法内裸名如 ISINSTANCE_CLASS_MAX 不再解析为 0）
- t.py CDefine Size/IsSigned 覆盖为 32 位有符号，修复 stub 生成 void 类型
- 新增 Test/TpvIsinstanceTest（TPV 侧 isinstance 回归测试）

Test/TpvIsinstanceTest/App/main.vp

@@ -0,0 +1,125 @@
+from stdint import *
+import t, c
+from t import CPtr, CInt, CExport
+import testcheck
+
+
+# ============================================================
+# TPV 侧 isinstance 内建函数测试（由 TransPyV.exe 编译）
+#
+# 验证 TPV 编译器生成的 isinstance IR：
+#   1. CVTable 自身 / 子类→基类
+#   2. 运行时多态（基类指针指向子类对象）
+#   3. 元组 (A, B)
+#   4. 多继承
+#   5. NoVTable 编译时静态判断
+# ============================================================
+
+
+# ========== CVTable 继承 ==========
+
+@t.CVTable
+class Animal:
+    Name: str
+
+    def __init__(self, name: str):
+        self.Name = name
+
+    def speak(self) -> str:
+        return "..."
+
+
+@t.CVTable
+class Dog(Animal):
+    def speak(self) -> str:
+        return "Woof"
+
+
+@t.CVTable
+class Cat(Animal):
+    def speak(self) -> str:
+        return "Meow"
+
+
+# ========== 多继承 ==========
+
+@t.CVTable
+class A:
+    a: CInt
+
+    def get_a(self) -> CInt:
+        return self.a
+
+
+@t.CVTable
+class B:
+    b: CInt
+
+    def get_b(self) -> CInt:
+        return self.b
+
+
+@t.CVTable
+class AB(A, B):
+    def __init__(self, a: CInt, b: CInt):
+        self.a = a
+        self.b = b
+
+
+# ========== NoVTable（编译时静态判断） ==========
+
+@t.NoVTable
+class Plain:
+    v: CInt
+
+
+def main() -> CInt | CExport:
+    testcheck.begin("TpvIsinstanceTest: TPV 侧 isinstance 测试")
+
+    # --- 1. 自身类型 + 子类→基类 ---
+    d: Dog | CPtr = Dog("dog")
+    testcheck.check(isinstance(d, Dog) == 1, "isinstance(d, Dog) 自身 OK",
+                    "isinstance(d, Dog) FAILED")
+    testcheck.check(isinstance(d, Animal) == 1, "isinstance(d, Animal) 子类→基类 OK",
+                    "isinstance(d, Animal) FAILED")
+    testcheck.check(isinstance(d, Cat) == 0, "isinstance(d, Cat) 不匹配 OK",
+                    "isinstance(d, Cat) FAILED")
+
+    # --- 2. 运行时多态：基类指针指向子类对象 ---
+    a: Animal | CPtr = (Animal | CPtr)(d)
+    testcheck.check(isinstance(a, Dog) == 1,
+                    "isinstance(Animal*, Dog 对象) 运行时多态 OK",
+                    "isinstance(Animal*, Dog) FAILED")
+    testcheck.check(isinstance(a, Animal) == 1,
+                    "isinstance(Animal*, Animal) 基类自身 OK",
+                    "isinstance(Animal*, Animal) FAILED")
+    testcheck.check(isinstance(a, Cat) == 0,
+                    "isinstance(Animal*, Cat) 运行时 False OK",
+                    "isinstance(Animal*, Cat) FAILED")
+
+    # --- 3. 元组 ---
+    testcheck.check(isinstance(d, (Cat, Dog)) == 1, "isinstance 元组命中 OK",
+                    "isinstance 元组 FAILED")
+    testcheck.check(isinstance(d, (Cat, A)) == 0, "isinstance 元组未命中 OK",
+                    "isinstance 元组未命中 FAILED")
+
+    # --- 4. 多继承 ---
+    ab: AB | CPtr = AB(1, 2)
+    testcheck.check(isinstance(ab, A) == 1, "isinstance(AB, A) 多继承 OK",
+                    "isinstance(AB, A) FAILED")
+    testcheck.check(isinstance(ab, B) == 1, "isinstance(AB, B) 多继承 OK",
+                    "isinstance(AB, B) FAILED")
+    testcheck.check(isinstance(ab, Animal) == 0, "isinstance(AB, Animal) False OK",
+                    "isinstance(AB, Animal) FAILED")
+    testcheck.check(ab.get_a() == 1 and ab.get_b() == 2, "AB 字段/方法正常 OK",
+                    "AB 字段/方法 FAILED")
+
+    # --- 5. NoVTable（编译时静态判断） ---
+    p: Plain | CPtr = Plain()
+    p.v = 42
+    testcheck.check(isinstance(p, Plain) == 1, "isinstance NoVTable 编译时 OK",
+                    "isinstance NoVTable FAILED")
+    testcheck.check(p.v == 42, "NoVTable 字段正常 OK", "NoVTable 字段 FAILED")
+
+    testcheck.ok("TPV 侧 isinstance 全部测试完成")
+    return testcheck.end()

Test/TpvIsinstanceTest/project.json

@@ -0,0 +1,29 @@
+{
+    "$schema": "https://raw.githubusercontent.com/TermiNexus/TransPyC/main/schemas/project-schema.json",
+    "name": "TpvIsinstanceTest",
+    "version": "1.0.0",
+    "source_dir": "./App",
+    "build_dir": "./.tpv_build",
+    "compiler": {
+        "cmd": "llc",
+        "flags": ["-filetype=obj", "-relocation-model=pic"]
+    },
+    "linker": {
+        "cmd": "clang++",
+        "flags": ["-Wl,--allow-multiple-definition", "-Wl,--unresolved-symbols=ignore-in-object-files", "-lmsvcrt", "-lucrt", "-lpthread", "-lmingwex", "-lkernel32", "-luser32", "-latomic"],
+        "output": "TpvIsinstanceTest.exe"
+    },
+    "includes": [
+        "../../includes"
+    ],
+    "target": {
+        "triple": "x86_64-pc-windows-gnu",
+        "datalayout": "e-m:w-p270:32:32-p271:32:32-p272:64:64-f80:128-n8:16:32:64-S128"
+    },
+    "options": {
+        "slice_level": 3,
+        "sha1_slice_level": 1,
+        "target": "llvm",
+        "strict_mode": true
+    }
+}