fix(generic): 泛型函数 Call 实参推断改为精确类型解析，移除名字子串猜测

原实现按被调名子串猜类型实参（含 Int→int、Float→double 等），把 CUInt64T/CInt16T 一律归成 int=i32，静默窄化/扩宽位宽（禁止静默默认原则）；CFloat32T 也会被猜成 double。

改为：把被调表达式本身交给注解解析器 resolve_annotation_type，命中**标量**才据其精确位宽经 _infer_scalar_type_name_from_spec（唯一真源）映射；非标量（构造/普通函数调用）或不可解析一律返回 None，由调用方汇总后 fail-fast 提示显式标注。行为变化：CUInt64T(x)/CInt16T(x) 等无等位宽裸名的转换实参不再被静默猜成 int。

App/lib/core/Gen/Class/ClassGenGeneric.vp

@@ -393,23 +393,23 @@ novirtual class ClassGenGeneric(ClassGenBase.ClassGenBase):
         if k == ast.ASTKind.Call:
             cl_f: ast.Call* = ast.Call*(arg_node)
             if cl_f.func is not None:
-                fn_id: str = None
-                if cl_f.func.kind() == ast.ASTKind.Name:
-                    fn_nm: ast.Name* = ast.Name*(cl_f.func)
-                    fn_id = fn_nm.id
-                elif cl_f.func.kind() == ast.ASTKind.Attribute:
-                    fn_at: ast.Attribute* = ast.Attribute*(cl_f.func)
-                    fn_id = fn_at.attr
-                if fn_id is not None:
-                    if string.strcmp(fn_id, "float") == 0 or string.strcmp(fn_id, "double") == 0 \
-                            or string.strstr(fn_id, "Float") is not None or string.strstr(fn_id, "Double") is not None:
-                        return "double"
-                    if string.strcmp(fn_id, "char") == 0 or string.strstr(fn_id, "Char") is not None:
-                        return "char"
-                    if string.strcmp(fn_id, "int") == 0 or string.strstr(fn_id, "Int") is not None \
-                            or string.strstr(fn_id, "UInt") is not None or string.strstr(fn_id, "Short") is not None \
-                            or string.strstr(fn_id, "Long") is not None:
-                        return "int"
+                fk_f: int = cl_f.func.kind()
+                # 只认「被调名本身可解析为**标量类型**」的转换调用（int(x) /
+                # t.CDouble(x) / CUInt64T(x) 等）：用注解解析器解析被调表达式，
+                # 命中标量即按**精确位宽**映射（复用 _infer_scalar_type_name_from_spec
+                # 这一唯一真源）；非标量（构造调用/普通函数调用）或不可解析一律
+                # None，交由调用方汇总后 fail-fast。
+                # 彻底移除原来的**名字子串猜测**（含 "Int" → int 等）：它把
+                # CUInt64T/CInt16T 一律归成 int=i32，静默窄化/扩宽位宽
+                # （现场：GenericOopTest `fxi2(a, b, CUInt64T(178900))` 的 T3=u64
+                # 被猜成 i32）。此处不做兜底猜测，宁缺毋错。
+                if (fk_f == ast.ASTKind.Name or fk_f == ast.ASTKind.Attribute) and trans is not None:
+                    cty_f: llvmlite.LLVMType* = self.Gen.TypeGenResolve.resolve_annotation_type(
+                        pool, cl_f.func, trans._imported_modules, trans._from_imports, trans, 0)
+                    if cty_f is not None:
+                        arena_c: TSpec.TypeSpecArena* = self.Gen.TypeGenBase.ensure_spec_arena()
+                        if arena_c is not None:
+                            return self._infer_scalar_type_name_from_spec(pool, TSpec.SpecFromLLVMType(arena_c, cty_f))
             return None
         return None