Vercel Flags: Platform-native feature flags

What this post added

Introduces Vercel Flags, a platform-native feature flagging system. Details server-side evaluation for zero performance impact, automatic flag registration from code, and the 'Precompute' pattern for static page variants. Also covers agent-native management via CLI and browser-based testing with Flags Explorer. Highlights internal usage by v0 for feature releases, AI model routing, and database migrations.