[backend] fix: 修复异常处理和类型转换问题

frontend/node_modules/graphemer/lib/GraphemerIterator.d.ts

@@ -0,0 +1,22 @@
+/**
+ * GraphemerIterator
+ *
+ * Takes a string and a "BreakHandler" method during initialisation
+ * and creates an iterable object that returns individual graphemes.
+ *
+ * @param str {string}
+ * @return GraphemerIterator
+ */
+declare class GraphemerIterator implements Iterator<string> {
+    private _index;
+    private _str;
+    private _nextBreak;
+    constructor(str: string, nextBreak: (str: string, index: number) => number);
+    [Symbol.iterator](): this;
+    next(): {
+        value: string;
+        done: boolean;
+    };
+}
+export default GraphemerIterator;
+//# sourceMappingURL=GraphemerIterator.d.ts.map