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。

NegativeTest/App/cases/call_float_to_int.vp

@@ -0,0 +1,7 @@
+import t, c
+
+def g(x: int) -> int:
+    return x
+
+def main() -> int:
+    return g(1.5)

NegativeTest/App/cases/call_too_few.vp

@@ -0,0 +1,7 @@
+import t, c
+
+def f(a: int, b: int) -> int:
+    return a + b
+
+def main() -> int:
+    return f(1)

NegativeTest/App/cases/call_too_many.vp

@@ -0,0 +1,7 @@
+import t, c
+
+def f(a: int, b: int) -> int:
+    return a + b
+
+def main() -> int:
+    return f(1, 2, 3)

NegativeTest/App/cases/call_wrong_type.vp

@@ -0,0 +1,7 @@
+import t, c
+
+def f(a: int, b: int) -> int:
+    return a + b
+
+def main() -> int:
+    return f("x", 2)

NegativeTest/App/cases/import_missing_module.vp

@@ -0,0 +1,5 @@
+import t, c
+import lib.core.Handles.HandlesStruct as HandlesStruct
+
+def main() -> int:
+    return 0

NegativeTest/App/cases/import_stale_path.vp

@@ -0,0 +1,6 @@
+import t, c
+# f8bca62 移动前的旧路径（文件在 lib/Stub/StubMerger/ 下）
+import lib.Stub.StubMergerStore as StubMergerStore
+
+def main() -> int:
+    return 0

NegativeTest/App/cases/import_wrong_path.vp

@@ -0,0 +1,5 @@
+import t, c
+import lib.NopeModule as NopeModule
+
+def main() -> int:
+    return 0

NegativeTest/App/cases/missing_return.vp

@@ -0,0 +1,4 @@
+import t, c
+
+def h(x: int) -> int:
+    x = x + 1

NegativeTest/App/cases/undefined_func.vp

@@ -0,0 +1,4 @@
+import t, c
+
+def main() -> int:
+    return foo(1)

NegativeTest/App/main.vp

@@ -0,0 +1,7 @@
+import t, c
+from stdint import *
+import stdio
+
+def main() -> int:
+    stdio.printf("NegativeTest baseline OK\n")
+    return 0

NegativeTest/project.json

@@ -0,0 +1,37 @@
+{
+    "name": "NegativeTest",
+    "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": "NegativeTest.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,
+        "target": "llvm",
+        "strict_mode": true
+    }
+}

NegativeTest/run_negative_tests.py

@@ -0,0 +1,71 @@
+# NegativeTest 反向测试运行器：对每个错误用例执行 TPC 单文件编译，
+# 断言"编译失败且输出诊断信息"。编译成功 = 编译器漏检（FAIL）。
+import os
+import subprocess
+import sys
+
+ROOT = os.path.dirname(os.path.dirname(os.path.dirname(os.path.abspath(__file__))))
+CASES_DIR = os.path.join(ROOT, 'Test', 'NegativeTest', 'App', 'cases')
+OUT_DIR = os.path.join(ROOT, 'Test', 'NegativeTest', '.out')
+os.makedirs(OUT_DIR, exist_ok=True)
+
+# 用例 -> 期望错误关键字（用于确认报错方向正确）
+EXPECT = {
+    'import_wrong_path.vp': ['NopeModule', '模块', 'import'],
+    'import_stale_path.vp': ['StubMergerStore', '模块', 'import'],
+    'import_missing_module.vp': ['HandlesStruct', '模块', 'import'],
+    'call_too_few.vp': ['参数', '少', '2', 'f'],
+    'call_too_many.vp': ['参数', '多', '3', 'f'],
+    'call_wrong_type.vp': ['类型', 'int', 'f'],
+    'call_float_to_int.vp': ['类型', 'int', 'g'],
+    'undefined_func.vp': ['foo', '未定义', 'NameError'],
+    'missing_return.vp': ['返回', 'return', '末尾'],
+}
+
+
+def main() -> int:
+    cases = sorted(f for f in os.listdir(CASES_DIR) if f.endswith('.vp'))
+    passed, failed, skipped = [], [], []
+    for case in cases:
+        src = os.path.join(CASES_DIR, case)
+        out_ll = os.path.join(OUT_DIR, case[:-3] + '.ll')
+        try:
+            r = subprocess.run(
+                [sys.executable, 'TransPyC.py', '-f', src, '-o', out_ll],
+                capture_output=True, text=True, cwd=ROOT, timeout=120,
+            )
+        except subprocess.TimeoutExpired:
+            failed.append((case, 'TIMEOUT', ''))
+            continue
+        err_text = (r.stderr or '') + (r.stdout or '')
+        if r.returncode == 0:
+            failed.append((case, 'COMPILED_OK(漏检)', err_text.strip()[-500:]))
+            continue
+        # 编译失败：检查是否报了我们预期的错误方向
+        lower = err_text.lower()
+        keywords = EXPECT.get(case, [])
+        hit = [k for k in keywords if k.lower() in lower]
+        if hit:
+            passed.append((case, 'PASS', hit, err_text.strip()[-300:]))
+        else:
+            skipped.append((case, 'ERR_BUT_UNEXPECTED', err_text.strip()[-300:]))
+
+    print('\n==== NegativeTest 结果 ====')
+    print(f'PASS(预期失败且方向正确): {len(passed)}')
+    for c, tag, hit, tail in passed:
+        print(f'  [PASS] {c}  命中关键字 {hit}')
+    print(f'FAIL(编译器漏检): {len(failed)}')
+    for c, tag, tail in failed:
+        print(f'  [FAIL] {c}  {tag}')
+        if tail:
+            print(f'         {tail}')
+    print(f'SKIP(报错但非预期方向): {len(skipped)}')
+    for c, tag, tail in skipped:
+        print(f'  [SKIP] {c}')
+        if tail:
+            print(f'         {tail}')
+    return 1 if failed else 0
+
+
+if __name__ == '__main__':
+    sys.exit(main())