Web: add HEIC media regression and doc fix (#38294)

* Web: add HEIC media normalization regression

* Docs: list HEIC input_image MIME types

* Update src/web/media.test.ts

Co-authored-by: greptile-apps[bot] <165735046+greptile-apps[bot]@users.noreply.github.com>

---------

Co-authored-by: greptile-apps[bot] <165735046+greptile-apps[bot]@users.noreply.github.com>

docs/gateway/openresponses-http-api.md

@@ -161,7 +161,7 @@ Supports base64 or URL sources:
 }
 ```
 
-Allowed MIME types (current): `image/jpeg`, `image/png`, `image/gif`, `image/webp`.
+Allowed MIME types (current): `image/jpeg`, `image/png`, `image/gif`, `image/webp`, `image/heic`, `image/heif`.
 Max size (current): 10MB.
 
 ## Files (`input_file`)

src/web/media.test.ts

@@ -16,6 +16,17 @@ import {
   optimizeImageToJpeg,
 } from "./media.js";
 
+const convertHeicToJpegMock = vi.fn();
+
+vi.mock("../media/image-ops.js", async () => {
+  const actual =
+    await vi.importActual<typeof import("../media/image-ops.js")>("../media/image-ops.js");
+  return {
+    ...actual,
+    convertHeicToJpeg: (...args: unknown[]) => convertHeicToJpegMock(...args),
+  };
+});
+
 let fixtureRoot = "";
 let fixtureFileCount = 0;
 let largeJpegBuffer: Buffer;
@@ -23,6 +34,7 @@ let largeJpegFile = "";
 let tinyPngBuffer: Buffer;
 let tinyPngFile = "";
 let tinyPngWrongExtFile = "";
+let fakeHeicFile = "";
 let alphaPngBuffer: Buffer;
 let alphaPngFile = "";
 let fallbackPngBuffer: Buffer;
@@ -76,6 +88,7 @@ beforeAll(async () => {
     .toBuffer();
   tinyPngFile = await writeTempFile(tinyPngBuffer, ".png");
   tinyPngWrongExtFile = await writeTempFile(tinyPngBuffer, ".bin");
+  fakeHeicFile = await writeTempFile(Buffer.from("fake-heic"), ".heic");
   alphaPngBuffer = await sharp({
     create: {
       width: 64,
@@ -178,6 +191,22 @@ describe("web media loading", () => {
     expect(result.contentType).toBe("image/jpeg");
   });
 
+  it("normalizes HEIC local files to JPEG output", async () => {
+    convertHeicToJpegMock.mockResolvedValueOnce(tinyPngBuffer);
+
+    const result = await loadWebMedia(fakeHeicFile, 1024 * 1024);
+
+    expect(convertHeicToJpegMock).toHaveBeenCalledTimes(1);
+    expect(result.kind).toBe("image");
+    expect(result.contentType).toBe("image/jpeg");
+    expect(result.fileName).toBe(path.basename(fakeHeicFile, ".heic") + ".jpg");
+    expect(result.buffer.length).toBeGreaterThan(0);
+    expect(result.buffer.equals(tinyPngBuffer)).toBe(false);
+    // Confirm the output is actually JPEG (magic bytes 0xFF 0xD8)
+    expect(result.buffer[0]).toBe(0xff);
+    expect(result.buffer[1]).toBe(0xd8);
+  });
+
   it("includes URL + status in fetch errors", async () => {
     const fetchMock = vi.spyOn(globalThis, "fetch").mockResolvedValueOnce({
       ok: false,