chore(test): 初始化回归测试仓（新增 .gitignore，TestsOverview.md 改为 README.md）

把 Test/ 纳入 https://git.gvsds.com/GVSDS/Viper_RegressionTesting 。

1) 新增 .gitignore —— 只保留测试源码，剔除全部构建产物：
   目录   **/output*/（output / output_opt / output_orig / output_verify / output_dbg）、
          **/temp*/（temp / temp_opt）、**/.tpv_build/
   二进制 *.exe *.obj *.o *.out *.a *.lib *.dll
   中间物 *.ll *.vpi *.pyi *.deps.txt *.deps.json *.doc.json *_sha1_map.txt
          _pyi_cache_v1.pkl _pyi_cache_v1.sig.json _shared_sym.json _phase1_manifest.json
   其它   build_all.txt（构建日志）、*.log、__pycache__/、*.bak、IDE 目录
   保留   App/*.vp、project.json / project_opt.json / project.vpj、README.md、两个 .py
   实测 `git add -A --dry-run`：196 个文件，无任何构建产物混入。

2) TestsOverview.md → README.md（作为仓库首页文档）。

3) SequentialRegressionTest.py：7 处 TestsOverview.md 引用同步改为 README.md
   （文档串、OVERVIEW 路径、read_test_order 文档与报错文案、argparse description、
   启动横幅）；同时修正入口路径 PROJECTRANS —— 旧值 <root>/Projectrans.py 已不存在，
   改为 <root>/TransPyC/Projectrans.py（与 regression_test.py:45-48 记录一致），
   否则本脚本会以 "can't open file" 全量失败。
   regression_test.py 无需改动：它按目录扫描 project.json 找项目，不引用该文档。

NoVTableCrossMixinTest/App/main.vp

@@ -0,0 +1,135 @@
+import t
+import stdio
+import string
+import testcheck
+
+
+# ============================================================
+# 复现：NoVTable 多继承下跨 Mixin self. 方法调用
+#
+# 缺陷：BaseB.caller 内 `self.helper()`（helper 定义在兄弟 Mixin BaseA，
+# 经 Combined 多继承组合）被 mangle 成 `<sha1>.BaseB.helper`
+# （用调用者自身/直接父类做前缀），而定义符号是 `<sha1>.BaseA.helper`
+# → ld.lld undefined symbol（TPV 侧 StmtGenMixin.translate_stmt 调
+# self.translate_return 同根因，符号成 StmtGenDeclMixin.translate_return）。
+# 期望：按实际定义类（BaseA）做前缀，或按最终组合类（Combined）。
+# ============================================================
+novirtual class BaseA:
+    a: t.CInt
+
+    def helper(self) -> int:
+        return self.a
+
+
+novirtual class BaseB:
+    b: t.CInt
+
+    def caller(self) -> int:
+        return self.helper()
+
+
+novirtual class Combined(BaseA, BaseB):
+    pass
+
+
+def test_cross_mixin_call():
+    testcheck.section("Test 1: cross-mixin self. call")
+    c: Combined = Combined()
+    c.a = 42
+    c.b = 7
+    testcheck.check(c.caller() == 42,
+                    "caller()==42 (BaseB->BaseA)",
+                    "cross-mixin call fail")
+
+
+# ============================================================
+# 扩展 Test 2：多级 Mixin 链（父类继承 + 兄弟）+ 字段写
+#
+# 覆盖 Handles 去壳核心要求：
+#   MixinB2 继承 MixinA2（1 级父类）；Combined2(MixinB2, MixinC2) 多继承。
+#   MixinC2.outer2 调兄弟 MixinB2.mid2（this_adjust 到 MixinB2 字段区），
+#   MixinB2.mid2 调父类 MixinA2.inner2（this_adjust 到 MixinA2 字段区），
+#   inner2 内写 self.a2（this_adjust 精确到组合类中 a2 字段）。
+# ============================================================
+novirtual class MixinA2:
+    a2: t.CInt
+
+    def inner2(self) -> int:
+        self.a2 = self.a2 + 10
+        return self.a2
+
+
+novirtual class MixinB2(MixinA2):
+    b2: t.CInt
+
+    def mid2(self) -> int:
+        return self.inner2() + self.b2
+
+
+novirtual class MixinC2:
+    c2: t.CInt
+
+    def outer2(self) -> int:
+        return self.mid2() + self.c2
+
+
+novirtual class Combined2(MixinB2, MixinC2):
+    pass
+
+
+def test_multilevel_chain():
+    testcheck.section("Test 2: multilevel mixin chain + field write")
+    c: Combined2 = Combined2()
+    c.a2 = 1
+    c.b2 = 2
+    c.c2 = 3
+    # outer2 -> mid2 -> inner2：inner2 写 a2(1->11)，mid2=11+2=13，outer2=13+3=16
+    testcheck.check(c.outer2() == 16,
+                    "outer2()==16 (C->B->A chain + field write)",
+                    "multilevel chain fail")
+
+
+# ============================================================
+# 扩展 Test 3：第二父类字段区偏移（this_adjust 非 0）+ 指针字段
+#
+# Combined3(PtrMixin, DataMixin)：PtrMixin 第一父类（字段区偏移 0），
+# DataMixin 第二父类（字段区偏移 = sizeof(PtrMixin)，非 0）。
+# DataMixin.get_val 内 self.val 需 this_adjust 到第二父类字段区。
+# ============================================================
+novirtual class PtrMixin:
+    name: t.CChar | t.CPtr
+
+    def get_name(self) -> t.CChar | t.CPtr:
+        return self.name
+
+
+novirtual class DataMixin:
+    val: t.CInt
+
+    def get_val(self) -> int:
+        return self.val
+
+
+novirtual class Combined3(PtrMixin, DataMixin):
+    pass
+
+
+def test_second_parent_offset():
+    testcheck.section("Test 3: second-parent field offset (this_adjust != 0)")
+    c: Combined3 = Combined3()
+    c.name = "hello"
+    c.val = 99
+    testcheck.check(string.strcmp(c.get_name(), "hello") == 0,
+                    "get_name()==hello (first parent)",
+                    "first parent fail")
+    testcheck.check(c.get_val() == 99,
+                    "get_val()==99 (second parent field offset)",
+                    "second parent this_adjust fail")
+
+
+def main() -> t.CInt:
+    testcheck.begin("NoVTableCrossMixinTest")
+    test_cross_mixin_call()
+    test_multilevel_chain()
+    test_second_parent_offset()
+    return testcheck.end()

NoVTableCrossMixinTest/project.json

@@ -0,0 +1,29 @@
+{
+    "$schema": "https://raw.githubusercontent.com/TermiNexus/TransPyC/main/schemas/project-schema.json",
+    "name": "NoVTableCrossMixinTest",
+    "version": "1.0.0",
+    "source_dir": "./App",
+    "build_dir": "./.tpv_build",
+    "compiler": {
+        "cmd": "llc",
+        "flags": ["-filetype=obj", "-relocation-model=pic"]
+    },
+    "linker": {
+        "cmd": "clang++",
+        "flags": ["-lmsvcrt", "-lucrt", "-lpthread", "-lmingwex", "-lkernel32", "-Wl,--allow-multiple-definition"],
+        "output": "NoVTableCrossMixinTest.exe"
+    },
+    "includes": [
+        "../../includes"
+    ],
+    "target": {
+        "triple": "x86_64-pc-windows-gnu",
+        "datalayout": "e-m:w-p270:32:32-p271:32:32-p272:64:64-i64:64-f80:128-n8:16:32:64-S128"
+    },
+    "options": {
+        "slice_level": 3,
+        "sha1_slice_level": 1,
+        "target": "llvm",
+        "strict_mode": true
+    }
+}