- **Architecture Refactoring**:
    - Implements `UnifiedPlayerSheetV2` as a standalone host to decouple the new player logic from the legacy implementation.
    - Introduces `SheetActionHandlers` and `FullPlayerRuntimePolicy` to centralize callback management and runtime behavior rules.
    - Extracts composition policies into `rememberFullPlayerCompositionPolicy` to granularly control when the full player is rendered vs. disposed.

- **Performance & UI Optimization**:
    - Adds `allowRealtimeUpdates` logic to disable expensive progress and wavy slider animations when the player is occluded by overlays (Queue/Cast) or partially collapsed.
    - Implements `reconcileQueueUiItems` to preserve `QueueUiItem` identity across queue updates, reducing unnecessary recompositions.
    - Dynamically swaps expensive smooth-corner shapes for simpler `RoundedCornerShape` during scrolls and reordering to improve frame rates.
    - Opt-out of expensive shadow blur effects when the player is expanded or the queue is active.

- **Interaction & Gestures**:
    - Refines `QueueSheetController` with a specific "quick flick" velocity threshold for easier queue expansion via short, fast upward gestures.
    - Optimizes `WavySliderExpressive` to accept an external `InteractionSource`, fixing stepping lag by deriving progress directly from state.
    - Adjusts drag activation thresholds and adds velocity tracking to the `FullPlayerContent` gesture area for improved responsiveness.

- **State Management**:
    - Refactors `MainActivity` state collection to use granular "slices" for `DismissUndoBar` and playback visibility, reducing root-level recompositions.
    - Streamlines telemetry state collection in `UnifiedPlayerQueueAndSongInfoHost` to only observe active timers when the queue is visible.

- **Miscellaneous**:
    - Adds `profileable` manifest entry for benchmarking.
    - Fixes an issue where `QueueBottomSheet` could snap to an invalid offset if measured height was not yet available during an open request.