fix: correct stale documentation URLs in error mapper (#69)

Two doc paths in the error mapper (`internal/api/transport/errors.go`)
404 after the docs restructure:

- SDK/internal errors: `getting-started/errors` → `platform/errors`
- `getResponse`: `platform/get-response` → `platform/task-polling`

No tests assert these URLs, so this is a two-line constant change.
Mirrors the same fix already shipped in the TypeScript and Python SDKs.

Co-authored-by: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

Author: felixsanz

internal/api/transport/errors.go

@@ -182,14 +182,14 @@ func DeriveCode(raw string) ErrorCode {
 
 const (
 	docsBase        = "https://runware.ai/docs"
-	sdkErrorDocPath = "getting-started/errors"
+	sdkErrorDocPath = "platform/errors"
 )
 
 var utilityDocPaths = map[string]string{
 	"modelSearch":       "platform/model-search",
 	"modelUpload":       "platform/model-upload",
 	"imageUpload":       "platform/image-upload",
-	"getResponse":       "platform/get-response",
+	"getResponse":       "platform/task-polling",
 	"accountManagement": "platform/account-management",
 }