chore: 整理配置与功能，优化B站解析流程

1. 从.gitignore移除config.example.toml并新增该示例配置文件
2. 新增项目规则文档说明开发环境要求
3. 修复config加载时的编码缺失问题
4. 重写bili_login.py，优化扫码登录流程与凭证输出
5. 重构B站解析器：简化下载逻辑，改用bilibili_api内置下载，优化音视频合并流程

bili_login.py

@@ -1,17 +1,39 @@
 import asyncio
 from bilibili_api import login_v2
 
+
 async def main():
     print("请使用 Bilibili 手机 App 扫描二维码登录")
+    print("=" * 40)
+
     qr = login_v2.QrCodeLogin()
-    demo = await qr.generate_qrcode()
-    await print( qr.get_qrcode_terminal())
-    
-    print("登录成功！")
-    print(f"sessdata = \"{credential.sessdata}\"")
-    print(f"bili_jct = \"{credential.bili_jct}\"")
-    print(f"buvid3 = \"{credential.buvid3}\"")
-    print(f"dedeuserid = \"{credential.dedeuserid}\"")
+
+    await qr.generate_qrcode()
+
+    print(qr.get_qrcode_terminal())
+    print("=" * 40)
+    print("等待扫码...")
+
+    while True:
+        state = await qr.check_state()
+        if state == login_v2.QrCodeLoginEvents.DONE:
+            print("登录成功！")
+            break
+        elif state == login_v2.QrCodeLoginEvents.SCAN:
+            print("已扫描，请确认登录...")
+        elif state == login_v2.QrCodeLoginEvents.TIMEOUT:
+            print("二维码已过期，请重新运行")
+            return
+        await asyncio.sleep(1)
+
+    credential = qr.get_credential()
+    print()
+    print("请将以下凭证添加到 config.toml 的 [bilibili] 配置块中：")
+    print(f'sessdata = "{credential.sessdata}"')
+    print(f'bili_jct = "{credential.bili_jct}"')
+    print(f'buvid3 = "{credential.buvid3 if credential.buvid3 else ""}"')
+    print(f'dedeuserid = "{credential.dedeuserid}"')
+
 
 if __name__ == '__main__':
     asyncio.run(main())