AI SDK 7 implementation and migration

Apply this skill to ai@7; use ai-sdk to resolve unknown versions and ai-sdk-6 for v6 maintenance. Match provider and UI package versions to the project. AI SDK 7 requires Node.js 22+ and AI SDK packages are ESM-only.

Read the resolved ai/docs/, provider docs and installed source/types first; each ai-sdk.dev/docs/... link in this skill has an offline copy under ai/docs/ (path mapping in ai-sdk). Harness, WorkflowAgent and migration guides live in ai/docs/03-ai-sdk-harnesses/, 03-agents/07-workflow-agent.mdx and 08-migration-guides/23-migration-guide-7-0.mdx; the companion packages ship only types. Use official docs or the matching repository tag when local docs are unavailable. Experimental package APIs need a fresh check before adding long-lived wrappers.