Add syntax recheck guard

src/models/note.ts

@@ -377,6 +377,18 @@ export const pack = async (
 	}
 	//#endregion
 
+	if ((() => { // Recheck syntax
+		const match = _note.text && _note.text.match(/<\/?!?nya>/ig) || [];
+		const stack: string[] = [];
+		for (const tag of [...match]
+			.map(x => x.toLocaleLowerCase()))
+				if (tag.includes('/')) {
+					if (stack.pop() !== tag.replace('/', ''))
+						return false;
+				} else
+					stack.push(tag);
+		return !stack.length;
+	})()) {
 		const nyamap: { [x: string]: string } = {
 		//#region nyaize: ja-JP
 			'な': 'にゃ',
@@ -416,6 +428,7 @@ export const pack = async (
 				_note.text += stack[0] && nyamap[head] || head;
 			}
 		}
+	}
 
 	if (!opts.skipHide) {
 		await hideNote(_note, meId);