fix: strip only internal prefix from model name for compatible providers (#243)

- Changed model.split('/').pop() to model.split('/').slice(1).join('/')
- Preserves vendor namespace in model names (e.g. moonshotai/Kimi-K2-Instruct)
- Also fixes multimodal image_url → input_image conversion for Responses API (#242)
- image_url parts from Chat Completions are now properly converted to input_image format

open-sse/executors/default.ts

@@ -82,7 +82,7 @@ export class DefaultExecutor extends BaseExecutor {
       this.provider?.startsWith?.("openai-compatible-") ||
       this.provider?.startsWith?.("anthropic-compatible-")
     ) {
-      const cleanModel = model.includes("/") ? model.split("/").pop() : model;
+      const cleanModel = model.includes("/") ? model.split("/").slice(1).join("/") : model;
       return { ...body, model: cleanModel };
     }
     return body;

open-sse/translator/request/openai-responses.ts

@@ -261,7 +261,13 @@ export function openaiToOpenAIResponsesRequest(
                 if (contentItem.type === "text") {
                   return { type: "input_text", text: toString(contentItem.text) };
                 }
-                if (contentItem.type === "image_url") return contentValue; // passthrough images
+                if (contentItem.type === "image_url") {
+                  const imgUrl = contentItem.image_url as string | { url?: string };
+                  return {
+                    type: "input_image",
+                    image_url: typeof imgUrl === "string" ? imgUrl : imgUrl?.url || "",
+                  };
+                }
                 return contentValue;
               })
             : [{ type: "input_text", text: "" }];