This pull request introduces significant changes to the video export functionality in the project, including the addition of custom resolution and frame rate options. The most important changes involve updates to the export process, the user interface for selecting export options, and modifications to the project configuration to support these new features.

Export Functionality Enhancements:

• Added output_width and output_height fields to the TimelineConfiguration struct to support custom video resolutions. (apps/desktop/src-tauri/src/recording.rs, apps/desktop/src/utils/tauri.ts, crates/project/src/configuration.rs, [1] [2] [3]
• Updated the render_video_to_channel function to use the custom frame rate specified in the project configuration. (crates/rendering/src/lib.rs, [1] [2] [3] [4]

User Interface Updates:

• Added new UI elements in the Header component to allow users to select resolution and frame rate options before exporting a video. (apps/desktop/src/routes/editor/Header.tsx, [1] [2] [3]
• Created new ResolutionOption and FPS_OPTIONS constants to populate the dropdown menus for resolution and frame rate selection. (apps/desktop/src/routes/editor/Header.tsx, apps/desktop/src/routes/editor/Header.tsxR10-R84)

Code Refactoring:

• Removed the old ExportButton component and integrated its functionality directly into the Header component, including the new export settings. (apps/desktop/src/routes/editor/Header.tsx, apps/desktop/src/routes/editor/Header.tsxL238-R442)
• Adjusted the ShareButton component to include the selected resolution and frame rate in the project configuration when sharing a video. (apps/desktop/src/routes/editor/Header.tsx, [1] [2]