feat(symbols): TPC 侧同步 renum 语法糖，renum X: 展开为 class X(t.REnum):

新增 _ExpandRenumBlocks（与 _ExpandUnionBlocks 同构，只改写头行）并接入 _ExpandSoftKeywordsImpl

行首 renum 的非 renum 名字: 形态响亮失败 SyntaxError（renum 不作标识符）

同步 TransPyV/includes 46cd4b4 的解析侧支持；ExpandSoftKeywords 文档改列八种展开

lib/core/SymbolUtils.py

@@ -163,7 +163,49 @@ def _ExpandUnionBlocks(Code: str) -> str:
     return ''.join(out)
 
 
-# ---------------------------------------------------------------------------
+# Viper soft keyword `renum` (statement-level reserved word): `renum X:` is exactly
+# `class X(t.REnum):` (same desugar target as TPV includes/ast/parser.vp:_parse_renumdef).
+# REnum members are ordinary class-body statements (nested `class V:` variants and
+# bare assignments like `None_ = 0`), so only the head line is rewritten.
+# `renum` is not used as an identifier anywhere in .vp sources.
+_RENUM_HEAD_RE: re.Pattern[str] = re.compile(
+    r'^(\s*)renum(\s+)([A-Za-z_]\w*)(\s*):([ \t]*(?:#.*)?)$'
+)
+_RENUM_PREFIX_RE: re.Pattern[str] = re.compile(r'^(\s*)renum\b')
+
+
+def _ExpandRenumBlocks(Code: str) -> str:
+    """Expand `renum Name:` into `class Name(t.REnum):` (same-line, line numbers kept).
+
+    Mirrors TPV _parse_renumdef: the body is an ordinary class body (variant classes
+    written as nested `class V:` plus payload-less assignments such as `None_ = 0`),
+    so only the head line is rewritten. A line starting with `renum` that is not the
+    exact `renum Name:` form fails loudly (renum is never an identifier in .vp sources).
+    """
+    if 'renum' not in Code:
+        return Code
+    out: list[str] = []
+    for Lineno, raw in enumerate(Code.splitlines(keepends=True), 1):
+        k: int = len(raw)
+        while k > 0 and (raw[k - 1] == '\n' or raw[k - 1] == '\r'):
+            k -= 1
+        body: str = raw[:k]
+        term: str = raw[k:]
+        head = _RENUM_HEAD_RE.match(body)
+        if head is not None:
+            out.append(f'{head.group(1)}class {head.group(3)}(t.REnum):{head.group(5)}{term}')
+            continue
+        if _RENUM_PREFIX_RE.match(body) is not None:
+            raise SyntaxError(
+                f"renum 语法错误（行 {Lineno}，原文: {body.strip()!r}）：应为 `renum 名字:`"
+                f"（等价于 `class 名字(t.REnum):`）。renum 是语句级保留字，成员写成嵌套 "
+                f"`class 变体:` 或无载荷赋值（如 `None_ = 0`）；非法形态一律终止编译（非静默）。"
+            )
+        out.append(raw)
+    return ''.join(out)
+
+
+# ---------------------------------------------------------------------------
 # define 常量声明（Viper 语法糖）——与 `NAME: t.CDefine = 值` **完全等价**
 # ---------------------------------------------------------------------------
 #   带类型   define NAME: T = <表达式>  →  NAME: T | t.CDefine = <表达式>
@@ -1248,7 +1290,7 @@ def EnumMemberCountMismatchError(ClassName: str, Visible: list[tuple[str, object
     )
 
 
-# ExpandSoftKeywords 是 Code 的纯函数（全程无全局可变状态，见其"五种展开"实现）：
+# ExpandSoftKeywords 是 Code 的纯函数（全程无全局可变状态，见其"八种展开"实现）：
 # 同一文件内容在一次编译里会被多处重复展开（Phase1 / Phase2 / 依赖扫描），
 # 缓存结果避免重复正则替换与 tokenize（cProfile：_ExpandTypeDescriptors 里的
 # tokenize.generate_tokens 全程 ~590 万次 TokenInfo._make）。纯函数缓存不改输出；有界防膨胀。
@@ -1282,7 +1324,11 @@ def ExpandSoftKeywords(Code: str) -> str:
        _ExpandArrayPrefixAnnotations）：只在注解位置生效（AnnAssign 的 ':' 之后 /
        形参 / '->' 之后 / 类字段），右值列表字面量**绝不改动**；无法脱糖的注解位置
        数组前缀**响亮失败**（SyntaxError，绝不静默产出 List 注解）。
-    七种展开都同行替换（长度可增，不增删换行），AST 行号映射保持有效。
+    8) `renum NAME:` → `class NAME(t.REnum):`：与手写 `class NAME(t.REnum):` 产出
+       **同一 AST/同一注册路径**（见 _ExpandRenumBlocks）。成员为普通类体（嵌套
+       `class 变体:` + 无载荷赋值）。行首 `renum` 的非 `renum 名字:` 形态**响亮失败**
+       （该词不在任何源码中作标识符）。
+    八种展开都同行替换（长度可增，不增删换行），AST 行号映射保持有效。
     """
     if not Code:
         return Code
@@ -1303,6 +1349,8 @@ def _ExpandSoftKeywordsImpl(Code: str) -> str:
         Code = _ExpandEnumBlocks(Code)
     if 'union' in Code:
         Code = _ExpandUnionBlocks(Code)
+    if 'renum' in Code:
+        Code = _ExpandRenumBlocks(Code)
     if 'define' in Code:
         Code = _ExpandDefineConsts(Code)
     if 'typedef' in Code: