Add org/enterprise fields to Connection struct from API

[ewega]

Summary

The CLI's \Connection\ struct only has \ID\ and \Name. The plugin API returns \organization\ and \�nterprise\ in GET responses. Adding these enables auto-resolving enterprise/org from existing connections.

Changes

• Add \Organization\ and \Enterprise\ fields to \Connection\ struct in \client.go\
• \discoverConnections\ populates \connChoice.enterprise\ from API responses
• Enterprise auto-resolved when scoping connections discovered via API (not just state file)

Acceptance Criteria

• \Connection\ struct includes \Organization\ and \Enterprise\ JSON fields
• \discoverConnections\ carries enterprise from API-discovered connections

[ewega]

Implemented in the enterprise support branch. Scope ID fix, connection testing, rate limit alignment, and Connection struct enrichment all shipped.