This commit implements a deep performance optimization of the UnifiedPlayerSheet to eliminate animation jank, following a detailed performance guide.

The key changes include:

1.  **State-Read Deferral:** Refactored `FullPlayerContent` and its children to accept state provider lambdas (`() -> T`) for frequently changing values like `currentPosition`, `isPlaying`, and `isFavorite`. This isolates recomposition to only the lowest-level composables that consume the state, drastically reducing the recomposition scope.

2.  **Stable Lambdas:** Replaced all inline lambda event handlers (e.g., `{ viewModel.playPause() }`) with stable function references (e.g., `viewModel::playPause`) to ensure parameter stability and allow Compose to skip recompositions more effectively.

3.  **Component Isolation:** Extracted `FullPlayerContent` and its related sub-composables into a separate file (`player/FullPlayerContent.kt`) for better modularity and code organization.

4.  **Graphics Optimization:** Removed unnecessary `compositingStrategy = CompositingStrategy.Offscreen` from `graphicsLayer` modifiers where simple alpha or translation transformations are used, reducing GPU and memory overhead.

This commit implements a deep performance optimization of the UnifiedPlayerSheet to eliminate animation jank, following a detailed performance guide.

The key changes include:

1.  **State-Read Deferral:** Refactored `FullPlayerContent` and its children to accept state provider lambdas (`() -> T`) for frequently changing values like `currentPosition`, `isPlaying`, and `isFavorite`. This isolates recomposition to only the lowest-level composables that consume the state, drastically reducing the recomposition scope.

2.  **Stable Lambdas:** Replaced all inline lambda event handlers (e.g., `{ viewModel.playPause() }`) with stable function references (e.g., `viewModel::playPause`) to ensure parameter stability and allow Compose to skip recompositions more effectively.

3.  **Component Isolation:** Extracted `FullPlayerContent` and its related sub-composables into a separate file (`player/FullPlayerContent.kt`) for better modularity and code organization.

4.  **Graphics Optimization:** Removed unnecessary `compositingStrategy = CompositingStrategy.Offscreen` from `graphicsLayer` modifiers where simple alpha or translation transformations are used, reducing GPU and memory overhead.

Fixes a bug where `collectAsState()` was called inside a non-composable lambda, causing a crash. The state is now correctly collected in the parent composable context.

This commit implements a deep performance optimization of the UnifiedPlayerSheet to eliminate animation jank, following a detailed performance guide.

The key changes include:

1.  **State-Read Deferral:** Refactored `FullPlayerContent` and its children to accept state provider lambdas (`() -> T`) for frequently changing values like `currentPosition`, `isPlaying`, and `isFavorite`. This isolates recomposition to only the lowest-level composables that consume the state, drastically reducing the recomposition scope.

2.  **Stable Lambdas:** Replaced all inline lambda event handlers (e.g., `{ viewModel.playPause() }`) with stable function references (e.g., `viewModel::playPause`) to ensure parameter stability and allow Compose to skip recompositions more effectively.

3.  **Component Isolation:** Extracted `FullPlayerContent` and its related sub-composables into a separate file (`player/FullPlayerContent.kt`) for better modularity and code organization.

4.  **Graphics Optimization:** Removed unnecessary `compositingStrategy = CompositingStrategy.Offscreen` from `graphicsLayer` modifiers where simple alpha or translation transformations are used, reducing GPU and memory overhead.

**Fixes:**
- Corrects a bug where `collectAsState()` was called inside a non-composable lambda. The state is now correctly collected in the parent composable context.
- Resolves a crash (`IllegalStateException: No ColorScheme provided`) caused by incorrect `CompositionLocal` scoping after refactoring. The `LocalMaterialTheme` is now made `internal` and shared correctly between files, eliminating the need for a duplicate private definition and ensuring the theme is properly provided to all child composables.

This commit refactors `UnifiedPlayerSheet.kt` by removing a significant amount of unused code and commented-out logic.

The key changes include:
- Removing unused imports, including `Trace`, `Toast`, and several animation-related imports.
- Deleting obsolete state collectors for dismissed songs/queues.
- Eliminating commented-out shape and radius calculations related to the player sheet and navigation bar, simplifying the component's layout logic.

This cleanup improves code readability and maintainability by removing deprecated and unnecessary code paths.