Add auto fullscreen option and simplify mouse movement handling

[Jayian1890]

This pull request introduces a new "Auto Full Screen" user setting, allowing users to automatically enter fullscreen mode when a stream starts or pointer lock is requested. The implementation adds UI, settings propagation, and runtime handling for this feature. Additionally, several improvements are made to pointer lock and mouse event handling, ensuring more predictable input behavior and removing unnecessary logic.

Auto Full Screen Feature:

• Added an "Auto Full Screen" toggle to the SettingsPage UI, allowing users to enable or disable automatic fullscreen on stream start or pointer lock requests (SettingsPage.tsx).
• Propagated the autoFullScreen setting throughout the app: initialization, runtime updates, and into the GfnWebRtcClient via ClientOptions and a new setAutoFullScreen method. [1] [2] [3] [4] [5] [6] [7] [8]
• Ensured that pointer lock and fullscreen flows respect the user's auto fullscreen preference, including on stream start and pointer lock attempts. [1] [2] [3] [4]

Pointer Lock and Mouse Event Handling:

• Removed "mirror mode" mouse delta accumulation logic and simplified pointer lock disabled state to only update local cursor tracking, not forward movement into the stream. [1] [2] [3]
• Updated mouse and wheel event handlers to only forward events to the stream when pointer lock is active, and to prevent unintended event forwarding in overlay or UI regions. [1] [2] [3]

These changes collectively give users more control over fullscreen behavior and improve pointer lock and mouse event handling for a more robust streaming experience.