✨ feat(a11y): add accessibility settings and theme improvements

Add comprehensive accessibility support across shared packages:
- A11y store with contrast, colorblind mode, and reduce motion settings
- A11yQuickToggles and A11ySettings UI components
- PillNavigation and PillDropdown components in shared-ui
- Calendar app updates to integrate new theme/a11y features

🤖 Generated with [Claude Code](https://claude.com/claude-code)

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

packages/shared-theme/src/index.ts

@@ -9,6 +9,12 @@ export type {
 	AppThemeConfig,
 	ThemeStore,
 	HSLValue,
+	// A11y Types
+	ContrastLevel,
+	ColorblindMode,
+	A11ySettings,
+	A11yStore,
+	A11yStoreConfig,
 } from './types';
 
 // Constants
@@ -21,9 +27,23 @@ export {
 	STORAGE_KEY_SUFFIX,
 } from './constants';
 
+// A11y Constants
+export {
+	A11Y_STORAGE_KEY_SUFFIX,
+	DEFAULT_A11Y_SETTINGS,
+	COLORBLIND_OPTIONS,
+	CONTRAST_OPTIONS,
+	HIGH_CONTRAST_CONFIG,
+	COLORBLIND_TRANSFORMS,
+	MOTION_DEFAULTS,
+} from './a11y-constants';
+
 // Store
 export { createThemeStore, APP_THEME_CONFIGS } from './store.svelte';
 
+// A11y Store
+export { createA11yStore } from './a11y-store.svelte';
+
 // Utils
 export {
 	isBrowser,
@@ -41,3 +61,16 @@ export {
 	getContrastColor,
 	generateThemeCSS,
 } from './utils';
+
+// A11y Utils
+export {
+	getSystemReducedMotion,
+	createReducedMotionListener,
+	applyMotionSettings,
+	applyHighContrast,
+	applyColorblindTransform,
+	applyA11yTransformations,
+	applyA11yAttributes,
+	loadA11yFromStorage,
+	saveA11yToStorage,
+} from './a11y-utils';