wk folders: wire remaining Projects & folders endpoints (update folder/project, list projects)

[zaynelt]

Summary

wk covers only 4 of the 7 endpoints behind the Projects & folders
Client Role permission. The three uncovered operations all correspond to
existing Workato platform APIs — they are simply not wired into wk yet
(so this is an enhancement, not blocked: platform-api).

Current coverage

Endpoint (Client Role permission)	wk	Command
GET /api/folders (list folders)	✅	wk folders list
POST /api/folders (create project or folder)	✅	wk folders create
DELETE /api/folders/:id (delete folder)	✅	wk folders delete
DELETE /api/projects/:id (delete project)	✅	wk folders delete (routed by is_project)
PUT /api/folders/:id (update folder)	❌	—
PUT /api/projects/:id (update project)	❌	—
GET /api/projects (list projects)	❌	projects only appear in wk folders list flagged is_project

Verified against internal/api/folders.go and the FolderService interface in
internal/api/client.go, which currently implements only List, Create,
Delete, and DeleteProject.

Proposed work

1. Update / rename — add an Update method and wk folders update
   (e.g. --name), routing to PUT /folders/:id or PUT /projects/:id by
   is_project (mirroring how delete already routes).
2. List projects — optionally add a dedicated GET /projects-backed path so
   projects can be listed via their own endpoint rather than inferred from the
   folder list.

Context

Surfaced while building docs/known-limitations.md (the permission → CLI
coverage map). See the Projects → Project assets → Projects & folders row.