v2.0.0

• Added Payload Resource support (.tres) as reusable snapshots.
• Added default payload save/load/clear support.
• Added sticky notifications (duration <= 0).
• Added instant notifications (animation_duration <= 0).
• Added sounds module (in, out, action, close) with payload and global fallback.
• Added dismiss option for action buttons and a close “X” button.
• Improved validation, logging, and demo scene with interactive payload building.