Function definePlatform

@suluk/platform — the platform generator (C051). Write one definePlatform manifest; the generator plans the shadcn-registry adds, generates the wired Hono entry, and merges each module's provision fragment into a single provision.config. The higher-level surface over C047's provision.config + the C050 registry: services: ["auth", "credits", "billing"] → a whole backend. The generated provision.config.ts imports mergeProvision from here.