fusion/.changeset/theme-system.md

@gsxdsm/fusion

@gsxdsm/fusion
minor

Add light mode toggle and theme selector with 8+ attractive color themes

• New theme modes: Dark, Light, and System (follows OS preference)
• 8 color themes: Default, Ocean, Forest, Sunset, Berry, Monochrome, High Contrast, and Solarized
• Quick theme toggle button in header
• Full theme selector in Settings > Appearance
• Theme preferences persist to localStorage
• No-FOUC inline script ensures correct theme before page render