fix: 添加禁用缓存响应头解决浏览器缓存问题

- 为 HTML 页面添加 Cache-Control: no-cache
- 添加 Pragma: no-cache
- 添加 Expires: 0
- 解决用户浏览器缓存旧版本 HTML 的问题

app.py

@@ -6,7 +6,7 @@
 作者：小白 🐶
 """
 
-from flask import Flask, render_template, redirect, url_for, request, flash
+from flask import Flask, render_template, redirect, url_for, request, flash, make_response
 from flask_login import LoginManager, UserMixin, login_user, login_required, logout_user, current_user
 from flask_sqlalchemy import SQLAlchemy
 from werkzeug.security import generate_password_hash, check_password_hash
@@ -18,6 +18,16 @@ app.config['SECRET_KEY'] = 'xiaobai-secret-key-2026'
 app.config['SQLALCHEMY_DATABASE_URI'] = 'sqlite:///users.db'
 app.config['SQLALCHEMY_TRACK_MODIFICATIONS'] = False
 
+# 禁用缓存 - 解决浏览器缓存问题
+@app.after_request
+def add_no_cache_headers(response):
+    """为 HTML 页面添加禁用缓存的响应头"""
+    if 'text/html' in response.content_type:
+        response.headers['Cache-Control'] = 'no-cache, no-store, must-revalidate'
+        response.headers['Pragma'] = 'no-cache'
+        response.headers['Expires'] = '0'
+    return response
+
 # 初始化数据库
 db = SQLAlchemy(app)