fix: add Azure channel support for /v1/responses/compact URL routing (#4149)

The Azure channel's GetRequestURL method only handled RelayModeResponses
but missed RelayModeResponsesCompact. This caused compact requests to
fall through to the generic deployments URL pattern, producing an
incorrect path that Azure returns 404 for.

This fix extends the existing responses API special handling to also
cover the compact mode, appending /compact to the subUrl when the relay
mode is ResponsesCompact.

Affected URLs (before → after):
- Normal Azure: /openai/deployments/{model}/responses/compact → /openai/v1/responses/compact
- cognitiveservices: same pattern → /openai/responses/compact
- Custom AzureResponsesVersion: properly respected for compact too

Co-authored-by: 彭俊杰 <pengjunjie@onero.com>

relay/channel/openai/adaptor.go

@@ -136,8 +136,8 @@ func (a *Adaptor) GetRequestURL(info *relaycommon.RelayInfo) (string, error) {
 			task = "chat/completions" + task
 		}
 
-		// 特殊处理 responses API
-		if info.RelayMode == relayconstant.RelayModeResponses {
+		// 特殊处理 responses API（包含 compact）
+		if info.RelayMode == relayconstant.RelayModeResponses || info.RelayMode == relayconstant.RelayModeResponsesCompact {
 			responsesApiVersion := "preview"
 
 			subUrl := "/openai/v1/responses"
@@ -150,6 +150,11 @@ func (a *Adaptor) GetRequestURL(info *relaycommon.RelayInfo) (string, error) {
 				responsesApiVersion = info.ChannelOtherSettings.AzureResponsesVersion
 			}
 
+			// compact 模式追加 /compact
+			if info.RelayMode == relayconstant.RelayModeResponsesCompact {
+				subUrl = subUrl + "/compact"
+			}
+
 			requestURL = fmt.Sprintf("%s?api-version=%s", subUrl, responsesApiVersion)
 			return relaycommon.GetFullRequestURL(info.ChannelBaseUrl, requestURL, info.ChannelType), nil
 		}