Moves `PUT /workflows/{id}` and `DELETE /workflows/{id}` onto
`@PublicApiController` and removes the legacy handlers, their hand-written spec
file and the now-unused request types. `workflows.id.yml` held only these two
operations, so the file and its `openapi.yml` entry go with them.
One behaviour change, deliberate: the update response now includes `shared`.
`WorkflowService.update` re-fetches with only the `tags` and `activeVersion`
relations, so `shared` came back undefined and the response mapper threw on
`workflow.shared.map(...)`. The update now re-fetches through
`findWorkflowForUser` for its response, as `getWorkflow` does and as
`createWorkflow` already does internally. The response gains a field; nothing is
removed.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>