fix(ast): 解析 PEP695 泛型函数类型参数 [T]，修复函数体被误提升模块级

- _parse_funcdef 消费并存储 def f[T](...) 的类型参数（与 class 解析器一致）

- FunctionDef 增加 type_params 字段（默认 None，非泛型函数不受影响）

- 修复: 之前 [T] 未消费导致 _expect_op(Colon) 失败、函数体被误提升到模块级，b = Box(42) 被注册为模块级全局，函数内赋值误报需用 global 声明

includes/ast/parser.vp

@@ -1929,6 +1929,27 @@ def _parse_funcdef(ps: Parser | t.CPtr, is_async: t.CInt) -> AST | t.CPtr:
         return None
     name: str = _cur_str(ps)
     _advance(ps)
+    # PEP 695 泛型函数类型参数: def add[T](a: T, b: T) — 解析并存入 type_params。
+    # （与 class 解析器一致；之前缺失此处理导致 _expect_op(Colon) 失败、函数体被
+    #   误提升到模块级——b = Box(42) 被当作模块级全局注册，函数内赋值误报
+    #   "需用 global 声明"。翻译时 type_params 映射到 int 兜底。）
+    type_params_fd: list[str] | t.CPtr = None
+    if _accept_op(ps, TokOp.Lsqb):
+        type_params_fd = list[str](ps.pool, 8)
+        while not _match_op(ps, TokOp.Rsqb):
+            if _cur_type(ps) == TokenType.EndMarker:
+                break
+            if _cur_type(ps) == TokenType.Name:
+                tp_name_fd: str = _cur_str(ps)
+                _advance(ps)
+                # 跳过可选 bound/约束: [T: bound] 或 [T: (A, B)]
+                if _match_op(ps, TokOp.Colon):
+                    _advance(ps)
+                    _parse_test(ps)
+                type_params_fd.append(tp_name_fd)
+            if not _accept_op(ps, TokOp.Comma):
+                break
+        _expect_op(ps, TokOp.Rsqb)
     args: AST | t.CPtr = None
     if _accept_op(ps, TokOp.LPar):
         args = _parse_varargslist(ps, 0)
@@ -1939,7 +1960,7 @@ def _parse_funcdef(ps: Parser | t.CPtr, is_async: t.CInt) -> AST | t.CPtr:
     _expect_op(ps, TokOp.Colon)
     dec_list: list[AST | t.CPtr] | t.CPtr = ps.pending_decorators
     ps.pending_decorators = None
-    node: FunctionDef | t.CPtr = FunctionDef(ps.pool, name, args, dec_list, returns, is_async)
+    node: FunctionDef | t.CPtr = FunctionDef(ps.pool, name, args, dec_list, returns, is_async, type_params_fd)
     _parse_suite_into_children(ps, node)
     _set_pos(node, lineno, col, 0, 0)
     return node

includes/ast/stmts.vp

@@ -307,12 +307,17 @@ class Expr(AST):
 
 class FunctionDef(AST):
     """FunctionDef(name: str, args: AST,
-                   decorator_list: list[AST | t.CPtr], returns: AST, flags: CInt)"""
+                   decorator_list: list[AST | t.CPtr], returns: AST, flags: CInt,
+                   type_params: list[str] | t.CPtr = None)
+
+    type_params: 泛型函数类型参数名列表（PEP 695 def f[T](...): 中的 [T]），
+                 None 表示非泛型函数。"""
     name:            str
     args:            AST | t.CPtr
     decorator_list:  list[AST | t.CPtr] | t.CPtr
     returns:         AST | t.CPtr
     flags:           t.CInt
+    type_params:     list[str] | t.CPtr
 
     def __new__(self, pool: memhub.MemManager | t.CPtr,
                 name: str, args: AST | t.CPtr,
@@ -326,12 +331,14 @@ class FunctionDef(AST):
     def __init__(self, pool: memhub.MemManager | t.CPtr,
                  name: str, args: AST | t.CPtr,
                  decorator_list: list[AST | t.CPtr] | t.CPtr,
-                 returns: AST | t.CPtr, is_async: t.CInt):
+                 returns: AST | t.CPtr, is_async: t.CInt,
+                 type_params: list[str] | t.CPtr = None):
         _init_ast(self, pool, 0, 0)
         self.name = _copy_str(pool, name)
         self.args = args
         self.decorator_list = decorator_list
         self.returns = returns
+        self.type_params = type_params
         if is_async:
             self.flags = FLAG_IS_ASYNC
         else: