[Feature] Integration with v0 system composables

[johnleider]

Summary

Enable v0 system composables to work together as a unified configuration layer via createV0Plugin or similar. Each system composable currently operates independently — they should share configuration and be cross-composable aware.

System Composables (v0.2.0 scope)

Composable	Purpose	Adapter Pattern	Integration Status
useTheme	Theme management, CSS variables	✅	#113 — needs RGB decomposition, auto on-colors, system detection, persist via useStorage
useLocale	i18n with interpolation	✅	#114 — provide locale to useDate, persist via useStorage, RTL detection
useDate	Date manipulation	✅	#116 — add date-fns + Luxon adapters, consume useLocale
useStorage	Persistent storage	✅	#117 — shared persist() API, namespace prefixing, SSR fallback
useBreakpoints	Responsive detection	❌	#118 — add mobileBreakpoint, *AndUp/*AndDown helpers, SSR support

Deferred

• useLogger — closed ([Integration] useLogger system composable integration #115), doesn't need system integration
• usePermissions — moved to v1.0.0 ([Integration] usePermissions system composable integration #119)

Goals

• Unified plugin initialization via createV0Plugin or similar
• Shared configuration object for all system composables
• useDate consumes useLocale for locale-aware formatting
• useTheme + useLocale persist preferences via useStorage
• Single provide/inject point for all system context

Example Usage

import { createV0 } from '@vuetify/v0'

const v0 = createV0({
  theme: { defaultTheme: 'light', themes: {...} },
  locale: { defaultLocale: 'en', messages: {...} },
  date: { adapter: 'dayjs' },
  storage: { adapter: 'localStorage', namespace: 'app' },
  breakpoints: { xs: 0, sm: 600, md: 960, lg: 1280, xl: 1920 },
})

app.use(v0)

Related Issues

• #113 useTheme integration
• #114 useLocale integration
• #116 useDate integration
• [Integration] useStorage system composable integration #117 useStorage integration
• [Integration] useBreakpoints system composable integration #118 useBreakpoints integration
• [Audit] useTheme - ensure parity with Vuetify createTheme #103-106 Audit issues
• [Integration] Convert Vuetify to use @vuetify/0 useTheme #108-111 Vuetify conversion issues

[johnleider]

All system composable integrations are complete.