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。

IterTest/App/main.vp

@@ -0,0 +1,52 @@
+import t
+import stdio
+import string
+import testcheck
+
+def test_for_in_string():
+    testcheck.section("Test 1: for-in string iteration")
+    s: t.CChar | t.CPtr = "Hello"
+    result: t.CInt = 0
+    for ch in s:
+        result += ch
+    # H=72, e=101, l=108, l=108, o=111 => 500
+    testcheck.check(result == 500, "for-in string (sum=500)", "for-in string (sum expect 500)")
+
+def test_for_in_char_ptr():
+    testcheck.section("Test 2: for-in char* iteration")
+    s: t.CChar | t.CPtr = "ABC"
+    chars: t.CArray[t.CInt, 4] = [0]
+    idx: t.CInt = 0
+    for ch in s:
+        if idx < 3:
+            chars[idx] = ch
+        idx += 1
+    testcheck.check(chars[0] == 65 and chars[1] == 66 and chars[2] == 67, "for-in char* (A=65 B=66 C=67)", "for-in char* (expect A=65 B=66 C=67)")
+
+def test_strcpy_for_in():
+    testcheck.section("Test 3: strcpy using for-in")
+    src: t.CChar | t.CPtr = "test"
+    # 手动实现 strcpy 用 for-in
+    import w32.win32memory
+    buf: t.CChar | t.CPtr = w32.win32memory.VirtualAlloc(None, 64, 12288, 4)
+    if t.CUInt64T(buf) == 0:
+        stdio.printf("SKIP: VirtualAlloc returned NULL\n")
+        return
+    string.memset(buf, 0, 64)
+    # 用 for-in 复制
+    p: t.CChar | t.CPtr = buf
+    for ch in src:
+        p[0] = ch
+        p += 1
+    p[0] = 0
+    # i8* == 是指针地址比较（C-Like 语义），字符串内容比较需显式 strcmp
+    testcheck.check(string.strcmp(buf, "test") == 0, "strcpy for-in (result=test)", "strcpy for-in (cmp mismatch)")
+
+import w32.win32memory
+
+def main() -> t.CInt:
+    testcheck.begin("IterTest: 指针迭代测试")
+    test_for_in_string()
+    test_for_in_char_ptr()
+    test_strcpy_for_in()
+    return testcheck.end()

IterTest/project.json

@@ -0,0 +1,40 @@
+{
+    "$schema": "https://raw.githubusercontent.com/TermiNexus/TransPyC/main/schemas/project-schema.json",
+    "name": "IterTest",
+    "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": "IterTest.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
+    }
+}