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。

ClosureTest/App/main.vp

@@ -0,0 +1,164 @@
+import t
+import stdio
+import testcheck
+
+# ============================================================
+# Test 1: global 在嵌套函数中
+# ============================================================
+g_val: t.CInt = 100
+
+def outer_modify_global():
+    global g_val
+    def inner_modify():
+        global g_val
+        g_val += 50
+    inner_modify()
+
+def test_global_in_nested():
+    testcheck.section("Test 1: global in nested function")
+    global g_val
+    g_val = 100
+    outer_modify_global()
+    testcheck.check(g_val == 150, "global nested (g_val == 150)", "global nested (expect 150)")
+
+# ============================================================
+# Test 2: nonlocal 在多层嵌套中
+# ============================================================
+def test_nonlocal_multi_level():
+    testcheck.section("Test 2: nonlocal multi-level")
+    x: t.CInt = 1
+    def level1():
+        nonlocal x
+        x += 10
+        def level2():
+            nonlocal x
+            x += 100
+            def level3():
+                nonlocal x
+                x += 1000
+            level3()
+        level2()
+    level1()
+    testcheck.check(x == 1111, "nonlocal multi (x == 1111)", "nonlocal multi (expect 1111)")
+
+# ============================================================
+# Test 3: global 和 nonlocal 混合
+# ============================================================
+g_mixed: t.CInt = 0
+
+def test_global_nonlocal_mixed():
+    testcheck.section("Test 3: global + nonlocal mixed")
+    global g_mixed
+    g_mixed = 0
+    local_var: t.CInt = 0
+    def modify_both():
+        nonlocal local_var
+        global g_mixed
+        g_mixed += 10
+        local_var += 20
+    modify_both()
+    modify_both()
+    testcheck.check(g_mixed == 20 and local_var == 40, "mixed (global==20 local==40)", "mixed (expect global=20 local=40)")
+
+# ============================================================
+# Test 4: lambda 捕获多个变量
+# ============================================================
+def test_lambda_multi_capture():
+    testcheck.section("Test 4: lambda multi-capture")
+    a: t.CInt = 10
+    b: t.CInt = 20
+    f = lambda: a + b
+    r: t.CInt = f()
+    testcheck.check(r == 30, "lambda multi-capture (a+b == 30)", "lambda multi-capture (expect 30)")
+
+# ============================================================
+# Test 5: lambda 带参数 + 捕获
+# ============================================================
+def test_lambda_arg_capture():
+    testcheck.section("Test 5: lambda arg + capture")
+    base: t.CInt = 100
+    add = lambda x: base + x
+    r: t.CInt = add(42)
+    testcheck.check(r == 142, "lambda arg+capture (100+42 == 142)", "lambda arg+capture (expect 142)")
+
+# ============================================================
+# Test 6: 嵌套函数返回值
+# ============================================================
+def test_nested_return():
+    testcheck.section("Test 6: nested function return")
+    x: t.CInt = 5
+    def double_x() -> t.CInt:
+        nonlocal x
+        x = x * 2
+        return x
+    r: t.CInt = double_x()
+    testcheck.check(r == 10 and x == 10, "nested return (r==10 x==10)", "nested return (expect r=10 x=10)")
+
+# ============================================================
+# Test 7: nonlocal 与循环变量
+# ============================================================
+def test_nonlocal_loop():
+    testcheck.section("Test 7: nonlocal with loop")
+    total: t.CInt = 0
+    def accumulate(n: t.CInt):
+        nonlocal total
+        for i in range(n):
+            total += i
+    accumulate(5)
+    accumulate(5)
+    # 0+1+2+3+4 = 10, twice = 20
+    testcheck.check(total == 20, "nonlocal loop (total == 20)", "nonlocal loop (expect 20)")
+
+# ============================================================
+# Test 8: global 数组操作
+# ============================================================
+g_arr: t.CArray[t.CInt, 4] = [0]
+
+def test_global_array():
+    testcheck.section("Test 8: global array")
+    global g_arr
+    g_arr[0] = 10
+    g_arr[1] = 20
+    g_arr[2] = 30
+    g_arr[3] = 40
+    total: t.CInt = g_arr[0] + g_arr[1] + g_arr[2] + g_arr[3]
+    testcheck.check(total == 100, "global array (total == 100)", "global array (expect 100)")
+
+# ============================================================
+# Test 9: 嵌套函数条件调用
+# ============================================================
+def test_nested_conditional():
+    testcheck.section("Test 9: nested conditional call")
+    result: t.CInt = 0
+    def set_result(val: t.CInt):
+        nonlocal result
+        result = val
+    if 1:
+        set_result(42)
+    else:
+        set_result(99)
+    testcheck.check(result == 42, "nested conditional (result == 42)", "nested conditional (expect 42)")
+
+# ============================================================
+# Test 10: lambda 链式调用
+# ============================================================
+def test_lambda_chain():
+    testcheck.section("Test 10: lambda chain")
+    f1 = lambda: 10
+    f2 = lambda: 20
+    r: t.CInt = f1() + f2()
+    testcheck.check(r == 30, "lambda chain (10+20 == 30)", "lambda chain (expect 30)")
+
+def main() -> t.CInt:
+    testcheck.begin("ClosureAdvancedTest: 高级闭包测试")
+    test_global_in_nested()
+    test_nonlocal_multi_level()
+    test_global_nonlocal_mixed()
+    test_lambda_multi_capture()
+    test_lambda_arg_capture()
+    test_nested_return()
+    test_nonlocal_loop()
+    test_global_array()
+    test_nested_conditional()
+    test_lambda_chain()
+    return testcheck.end()

ClosureTest/project.json

@@ -0,0 +1,40 @@
+{
+    "$schema": "https://raw.githubusercontent.com/TermiNexus/TransPyC/main/schemas/project-schema.json",
+    "name": "ClosureTest",
+    "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",
+            "-lmsvcrt",
+            "-lucrt",
+            "-lpthread",
+            "-lmingwex",
+            "-lkernel32",
+            "-luser32"
+        ],
+        "output": "ClosureTest.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
+    }
+}