feat: add dark note card colors and getNoteColor helper

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

src/lib/utils/colors.test.ts

@@ -0,0 +1,25 @@
+import { describe, it, expect } from 'vitest';
+import { getNoteColor, NOTE_COLORS, NOTE_COLORS_DARK } from '$lib/utils/colors.js';
+
+describe('getNoteColor', () => {
+	it('returns light color when isDark is false', () => {
+		expect(getNoteColor('default', false)).toBe('#faf5eb');
+		expect(getNoteColor('coral', false)).toBe('#faafa8');
+	});
+
+	it('returns dark color when isDark is true', () => {
+		expect(getNoteColor('default', true)).toBe('#2a2520');
+		expect(getNoteColor('coral', true)).toBe('#4a2522');
+	});
+
+	it('returns default color for unknown color name', () => {
+		expect(getNoteColor('unknown' as any, false)).toBe('#faf5eb');
+		expect(getNoteColor('unknown' as any, true)).toBe('#2a2520');
+	});
+
+	it('has matching keys in light and dark color maps', () => {
+		const lightKeys = Object.keys(NOTE_COLORS).sort();
+		const darkKeys = Object.keys(NOTE_COLORS_DARK).sort();
+		expect(lightKeys).toEqual(darkKeys);
+	});
+});

src/lib/utils/colors.ts

@@ -15,6 +15,26 @@ export const NOTE_COLORS: Record<NoteColor, { bg: string; label: string }> = {
 	chalk: { bg: '#efeff1', label: 'Chalk' }
 };
 
+export const NOTE_COLORS_DARK: Record<NoteColor, { bg: string; label: string }> = {
+	default: { bg: '#2a2520', label: 'Default' },
+	coral: { bg: '#4a2522', label: 'Coral' },
+	peach: { bg: '#4a3020', label: 'Peach' },
+	sand: { bg: '#3a3520', label: 'Sand' },
+	mint: { bg: '#2a3a22', label: 'Mint' },
+	sage: { bg: '#223a32', label: 'Sage' },
+	fog: { bg: '#222e3a', label: 'Fog' },
+	storm: { bg: '#1e2a35', label: 'Storm' },
+	dusk: { bg: '#352540', label: 'Dusk' },
+	blossom: { bg: '#3a2830', label: 'Blossom' },
+	clay: { bg: '#302e28', label: 'Clay' },
+	chalk: { bg: '#2e2e30', label: 'Chalk' }
+};
+
+export function getNoteColor(color: NoteColor, isDark: boolean): string {
+	const map = isDark ? NOTE_COLORS_DARK : NOTE_COLORS;
+	return (map[color] ?? map.default).bg;
+}
+
 export const COLOR_OPTIONS = Object.entries(NOTE_COLORS).map(([value, { label }]) => ({
 	value: value as NoteColor,
 	label