Website: Seasonal Theme Reset

what changed

The colorTheme store in @ewanc26/ui now tracks whether the active theme was auto-applied by the seasonal logic or chosen explicitly. This lands as a new isSeasonal flag and a resetToSeasonal() method — all internal state, no public API surface change.

On the website side, ColorThemeToggle.svelte picks this up and shows a subtle hint at the top of the dropdown when the theme is seasonal: a sparkle icon and "Currently seasonal — click to keep". Clicking it calls setTheme with the current value, writing it to localStorage and clearing the isSeasonal flag. The theme itself doesn't change — you're just pinning it.

Useful if you happen to like the season you're in.