fix: personalize fullscreen mode instead of windowed mode

[BLumia]

应当对全屏模式进行处理，而非小窗口模式。

Log:

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关键摘要:

• 变量命名不一致：原代码中使用的是 "WindowedFrameApplicationWindow"，而修改后的是 "FullscreenFrameApplicationWindow"。建议保持命名一致性，以避免混淆。
• 缺少对新变量 fullscreenFrameWindow 的定义或初始化：在修改后的代码中，fullscreenFrameWindow 没有被定义和初始化，这可能会导致编译错误或运行时错误。
• 缺少对新变量 fullscreenFrameWindow 的使用注释：虽然变量名已经表明了它的用途，但在实际代码中添加一些注释来解释为什么选择这个窗口对象可能是有帮助的。

是否建议立即修改:

• 是

[deepin-ci-robot]

[APPROVALNOTIFIER] This PR is NOT APPROVED

This pull-request has been approved by: BLumia, justforlxz

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