fix(kiro): preserve inline images in OpenAI MITM

Forward Kiro userInputMessage.images as OpenAI-compatible image_url content parts.

src/mitm/handlers/kiro.js

@@ -180,6 +180,14 @@ function withInitialFrame(state, frames) {
 
 // ─── CodeWhisperer → OpenAI conversion ───────────────────────────────────────
 
+const INLINE_IMAGE_MIME_BY_FORMAT = new Map([
+  ["png", "image/png"],
+  ["jpeg", "image/jpeg"],
+  ["jpg", "image/jpeg"],
+  ["gif", "image/gif"],
+  ["webp", "image/webp"],
+]);
+
 /**
  * Safely stringify a tool-call input value.
  * OpenAI expects `function.arguments` to be a JSON string, never an object.
@@ -214,9 +222,32 @@ function convertUserInputMessage(uim) {
     });
   }
 
+  const images = Array.isArray(uim.images) ? uim.images : [];
+  const imageParts = images
+    .filter(image => image !== null
+      && typeof image === "object"
+      && !Array.isArray(image)
+      && image.source !== null
+      && typeof image.source === "object"
+      && !Array.isArray(image.source)
+      && INLINE_IMAGE_MIME_BY_FORMAT.has(image.format)
+      && typeof image.source.bytes === "string"
+      && image.source.bytes.length > 0)
+    .map(image => ({
+      type: "image_url",
+      image_url: {
+        url: `data:${INLINE_IMAGE_MIME_BY_FORMAT.get(image.format)};base64,${image.source.bytes}`,
+      },
+    }));
+
   // Emit user text only if it exists alongside OR when there are no tool results
   const text = (uim.content || "").trim();
-  if (text || toolResults.length === 0) {
+  if (imageParts.length > 0) {
+    const content = [];
+    if (text) content.push({ type: "text", text });
+    content.push(...imageParts);
+    out.push({ role: "user", content });
+  } else if (text || toolResults.length === 0) {
     out.push({ role: "user", content: text });
   }