- **Full Player UI**:
    - Replaces `Crossfade` with manual alpha blending in `DelayedContent` for smoother transitions between placeholders and actual content.
    - Implements logic to track collapse/expand direction, allowing placeholders to be triggered at a specific "close threshold" when the player is dismissed.
    - Refines placeholder components (`AlbumPlaceholder`, `MetadataPlaceholder`, `ProgressPlaceholder`, `ControlsPlaceholder`) to better match the visual density and layout of real components, including landscape support and audio metadata chips.
    - Adds `graphicsLayer` transformations to placeholders to synchronize their appearance with the sheet expansion fraction.

- **Settings & Configuration**:
    - Adds "Close threshold" slider to Experimental Settings to control when placeholders appear during collapse.
    - Introduces a toggle to enable/disable placeholder delay specifically when closing the player.
    - Renames "Full player content appear threshold" to "Expand threshold" for clarity.

- **Data & State**:
    - Updates `FullPlayerLoadingTweaks` and `UserPreferencesRepository` to persist new threshold and close-behavior preferences.
    - Adds corresponding setter methods in `SettingsViewModel`.

- **UI Refinements**:
    - Adjusts padding in `BottomToggleRow` and layout spacing in `FullPlayerContent` for better visual alignment.