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。

DocTest/App/main.vp

@@ -0,0 +1,69 @@
+import t
+import stdio
+import string
+import c
+import testcheck
+import remote
+
+
+# 同模块函数（有 docstring）
+def local_func() -> int:
+    "Local function docstring."
+    return 0
+
+
+# 同模块函数（无 docstring）
+def no_doc_func() -> int:
+    return 0
+
+
+# 同模块类（有 docstring）
+class LocalClass:
+    "Local class docstring."
+    value: t.CInt
+
+    def local_method(self) -> int:
+        "Local method docstring."
+        return 0
+
+
+def _check_doc_adaptive(name: str, doc: str, expected: str):
+    """自适应检查 docstring：非空时验证匹配，空时视为优化剥离"""
+    if doc is None:
+        testcheck.ok(f"{name}: __doc__ optimized out (null)")
+        return
+    if string.strcmp(doc, expected) == 0:
+        testcheck.ok(f"{name}: __doc__ matches")
+    else:
+        testcheck.fail(f"{name}: __doc__ mismatch (got '{doc}', expected '{expected}')")
+
+
+def _check_doc_null(name: str, doc: str):
+    """检查 docstring 为 null（无 docstring 的符号）"""
+    if doc is None:
+        testcheck.ok(f"{name}: __doc__ is null")
+    else:
+        testcheck.fail(f"{name}: __doc__ should be null but got '{doc}'")
+
+
+def test_local_doc():
+    testcheck.section("Local __doc__")
+    _check_doc_adaptive("local_func", local_func.__doc__, "Local function docstring.")
+    _check_doc_adaptive("LocalClass", LocalClass.__doc__, "Local class docstring.")
+    _check_doc_adaptive("LocalClass.local_method", LocalClass.local_method.__doc__, "Local method docstring.")
+    _check_doc_null("no_doc_func", no_doc_func.__doc__)
+
+
+def test_cross_module_doc():
+    testcheck.section("Cross-module __doc__")
+    _check_doc_adaptive("remote.remote_func", remote.remote_func.__doc__, "Remote function docstring.")
+    _check_doc_adaptive("remote.RemoteClass", remote.RemoteClass.__doc__, "Remote class docstring.")
+    _check_doc_adaptive("remote.RemoteClass.remote_method", remote.RemoteClass.remote_method.__doc__, "Remote method docstring.")
+    _check_doc_null("remote.no_doc_func", remote.no_doc_func.__doc__)
+
+
+def main() -> t.CInt:
+    testcheck.begin("DocTest: __doc__ magic string test")
+    test_local_doc()
+    test_cross_module_doc()
+    return testcheck.end()

DocTest/App/remote.vp

@@ -0,0 +1,19 @@
+import t
+
+
+def remote_func() -> int:
+    "Remote function docstring."
+    return 0
+
+
+class RemoteClass:
+    "Remote class docstring."
+    value: t.CInt
+
+    def remote_method(self) -> int:
+        "Remote method docstring."
+        return 0
+
+
+def no_doc_func() -> int:
+    return 0

DocTest/project.json

@@ -0,0 +1,39 @@
+{
+    "$schema": "https://raw.githubusercontent.com/TermiNexus/TransPyC/main/schemas/project-schema.json",
+    "name": "DocTest",
+    "version": "1.0.0",
+    "source_dir": "./App",
+    "build_dir": "./.tpv_build",
+    "compiler": {
+        "cmd": "llc",
+        "flags": [
+            "-filetype=obj"
+        ]
+    },
+    "linker": {
+        "cmd": "clang++",
+        "flags": [
+            "-Wl,--allow-multiple-definition",
+            "-lmsvcrt",
+            "-lucrt",
+            "-lpthread",
+            "-lmingwex",
+            "-lkernel32",
+            "-luser32"
+        ],
+        "output": "DocTest.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": 0,
+        "sha1_slice_level": 1,
+        "target": "llvm",
+        "strict_mode": true
+    }
+}

DocTest/project_opt.json

@@ -0,0 +1,40 @@
+{
+    "$schema": "https://raw.githubusercontent.com/TermiNexus/TransPyC/main/schemas/project-schema.json",
+    "name": "DocTestOpt",
+    "version": "1.0.0",
+    "source_dir": "./App",
+    "temp_dir": "./temp_opt",
+    "output_dir": "./output_opt",
+    "compiler": {
+        "cmd": "llc",
+        "flags": [
+            "-filetype=obj"
+        ]
+    },
+    "linker": {
+        "cmd": "clang++",
+        "flags": [
+            "-Wl,--allow-multiple-definition",
+            "-lmsvcrt",
+            "-lucrt",
+            "-lpthread",
+            "-lmingwex",
+            "-lkernel32",
+            "-luser32"
+        ],
+        "output": "DocTestOpt.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
+    }
+}