@kubb/plugin-ky: slim ky client plugin with the RequestResult contract

[stijnvanhulle]

Part of #384 — depends on #386 (shared foundation). Mirrors #387/#388 for ky; first ky support in the repo (today it is only mentioned as a custom importPath example).

Summary

New package @kubb/plugin-ky: a slim client plugin pinned to ky, generating functions with the grouped options object and RequestResult contract from #384. Same option surface as the other slim plugins: output, group, include/exclude/override, baseURL, parser, macros.

Scope

• Package scaffold identical in shape to @kubb/plugin-fetch: slim fetch client plugin with the RequestResult contract #387.
• Ky runtime in src/clients/ky.ts + templates/ky.source.ts, built from the shared runtime sources in internals/client: shared generator foundation for the slim client plugins #386:
  • default client instance + createClient/setConfig, per-call client override
  • transport: the config accepts a user-provided ky instance, defaulting to ky — this is also the pass-through for ky-specific behavior (retry, hooks, prefixUrl):

import ky from 'ky'
import { createClient } from './.kubb/client'

const client = createClient({
  transport: ky.extend({ retry: 3, hooks: { beforeRequest: [addTracing] } }),
})

• interceptors via the shared stack from internals/client: shared generator foundation for the slim client plugins #386, layered on top of whatever the provided instance already does
• querySerializer/bodySerializer, auth hook (Slim client plugins: auth from the spec (security metadata + auth() callback) #395), validator hooks (Zod parser support in the slim client plugins (success-only response, request inputs) #390)
• ky throws HTTPError on non-2xx by default — with throwOnError: true (our default) normalize it to ResponseError with the parsed typed body, so the thrown shape is identical across all three plugins
• throwOnError: false uses throwHttpErrors: false and assembles { data, error, request, response }
• native Request/Response on the result (ky exposes both)
• macros?: Array<ast.Macro> registered via ctx.setMacros (foundation wiring, internals/client: shared generator foundation for the slim client plugins #386) — the standard AST-transform hook, authored with ast.defineMacro.
• The runtime is always bundled into .kubb/client.ts (same as @kubb/plugin-fetch: slim fetch client plugin with the RequestResult contract #387 — no bundle option); ky itself stays a regular peer import in the generated code, never inlined.
• Generators (grouped options signature) and example project — same checklist as @kubb/plugin-fetch: slim fetch client plugin with the RequestResult contract #387. Options docs live in the platform repo (kubb-labs/platform): apps/kubb.dev/plugins/plugin-ky.md + extensions/plugins/plugin-ky.yaml (tracked under Docs and examples for the slim client plugins #393); the old plugins/*.yaml + extension.yaml mechanism was removed in chore: stop shipping extension.yaml and remove the yaml generator #398.

Done when

• pnpm build, pnpm test, pnpm typecheck green for the package
• Runtime tests cover: HTTPError → ResponseError normalization, throwOnError: false, custom ky instance via transport (retry/hooks respected), interceptors, per-call client override
• Generated output snapshots match the grouped-options RequestResult contract in both modes, with the runtime inlined in .kubb/client.ts
• Options documented on the plugin's kubb.dev page in the platform repo (Docs and examples for the slim client plugins #393)
• Example project generates and typechecks