Remove Deprecated api Client

Goal

Replace openapi-fetch api client with SDK methods in 10 modules, delete deprecated code.

Background

• SDK has 3 methods, UI uses 21 endpoints
• 18 endpoints missing from SDK
• 10 modules need migration

SDK Additions Needed

Endpoints (18)

• Provider builds: POST/GET builds, GET build/{id}, GET build/{id}/logs (streaming)
• Providers: GET/POST/DELETE, GET/DELETE /{id}
• Provider variables: GET/PUT /{id}/variables
• Configurations: GET /system
• Feedback: POST
• Files: POST, DELETE /{id}
• Variables: GET, PUT
• Connectors: GET/POST, DELETE /{id}, POST /{id}/connect, POST /{id}/disconnect
• User: GET
• Contexts: GET, PATCH /{id}, DELETE /{id}, GET /{id}/history

Features

• Move ensureData to SDK
• Streaming: return ReadableStream
• File uploads: auto-detect File/Blob, create FormData

Migration

1. Add missing methods to SDK
2. Update modules:
   • provider-builds/api
   • providers/api
   • configurations/api
   • feedback/api
   • files/api
   • variables/api
   • connectors/api
   • users/api