Implements ConnectWiseClient in services/psa/connectwise/client.py with:
- API key auth (Base64 companyId+publicKey:privateKey) + clientId header
- Accept header pinned to CW API version 2025.16
- Dynamic base URL resolution via /login/companyinfo (cloud vs on-premise)
- SSRF prevention: validates against known CW domains, rejects private IPs
- Retry with exponential backoff for timeouts and 5xx errors
- 429 rate limit handling with Retry-After header respect
- Error mapping: 401/403/404/429/5xx to typed PSA exceptions
- Paginated GET with while-loop pattern (max 1000 per page)
- JSON Patch array format for PATCH requests
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
