[Integration] useBreakpoints system composable integration

[johnleider]

Summary

Integrate useBreakpoints with the v0 plugin system and ensure feature parity with Vuetify's createDisplay for breakpoint-related concerns.

Integration Points

• Accept configuration from unified v0 plugin options (custom thresholds, mobile breakpoint)
• Add mobileBreakpoint option — configurable threshold (number or breakpoint name) that exposes a reactive mobile boolean
• Add *AndUp / *AndDown convenience booleans (smAndUp, mdAndDown, etc.)
• SSR support — accept clientWidth / clientHeight for server-side rendering

Out of Scope (Vuetify-level concerns)

• Platform detection (android, ios, chrome, electron, etc.) — device sniffing is not a breakpoint concern, Vuetify can layer this on top
• Per-component mobile override via props — Vuetify's useDisplay(props) pattern, handled at the framework level

Related

• #104 - Audit useBreakpoints parity with Vuetify createDisplay
• [Integration] Convert Vuetify to use @vuetify/0 useBreakpoints #109 - Convert Vuetify to use v0 useBreakpoints