Sheet Notes for D&D 5th Edition

Adds a Notes tab to D&D 5e character sheets with note-taking and tracker functionality.

• Notes Tab: New tab on character sheets for taking notes
• Categories: Organize notes into custom categories like "Session Notes", "Backstory", "Quests"
• Drag & Drop: Move notes between categories
• Rich Text: Full text editor with formatting
• Smart Display: Empty categories are hidden by default
• Sheet Integration: Works on both PC and NPC sheets, matches D&D 5e styling