fix(gateway): route openai image streams with images surface

apps/aether-gateway/src/ai_serving/planner/specialized/image/request.rs

@@ -172,7 +172,7 @@ pub(super) async fn resolve_local_openai_image_candidate_payload_parts(
     } else if is_grok {
         build_grok_upstream_url(transport, GROK_CHAT_PATH)
     } else {
-        build_openai_image_upstream_url(transport, parts.uri.query())
+        build_openai_image_upstream_url(transport, Some(parts.uri.path()), parts.uri.query())
     };
     let mut provider_request_body = if is_chatgpt_web {
         match build_chatgpt_web_image_request_body(parts, body_json, body_base64) {

apps/aether-gateway/src/ai_serving/planner/standard/family/request.rs

@@ -625,7 +625,8 @@ async fn resolve_local_gemini_image_to_openai_image_candidate_payload_parts(
     };
 
     let upstream_is_stream = true;
-    let upstream_url = build_openai_image_upstream_url(transport, None);
+    let upstream_url =
+        build_openai_image_upstream_url(transport, Some("/v1/images/generations"), None);
     let effective_headers = input.effective_headers(&parts.headers);
     let Some(mut provider_request_headers) =
         build_openai_image_headers(ProviderOpenAiImageHeadersInput {

apps/aether-gateway/src/ai_serving/planner/standard/openai/responses/decision/request.rs

@@ -739,7 +739,11 @@ async fn resolve_openai_responses_to_openai_image_payload_parts(
     let upstream_url = if is_chatgpt_web {
         chatgpt_web_image_internal_url(&transport.endpoint.base_url)
     } else {
-        build_openai_image_upstream_url(transport, parts.uri.query())
+        build_openai_image_upstream_url(
+            transport,
+            Some("/v1/images/generations"),
+            parts.uri.query(),
+        )
     };
     let Some(mut provider_request_headers) =
         build_openai_image_headers(ProviderOpenAiImageHeadersInput {