chore: add culori dependency for color manipulation

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

package.json

@@ -31,6 +31,7 @@
 		"@tailwindcss/vite": "^4.1.18",
 		"@triplit/cli": "^1.0.61",
 		"@types/better-sqlite3": "^7.6.13",
+		"@types/culori": "^4.0.1",
 		"@types/node": "^24",
 		"@vitest/browser-playwright": "^4.0.18",
 		"better-auth": "^1.4.18",
@@ -66,6 +67,7 @@
 		"@triplit/svelte": "^1.0.50",
 		"better-sqlite3": "^12.6.2",
 		"carta-md": "^4.11.1",
+		"culori": "^4.0.2",
 		"isomorphic-dompurify": "^3.0.0",
 		"svelte-confetti": "^2.3.2",
 		"valibot": "^1.2.0"