Fix markdown image rendering without resolver

Co-Authored-By: Paperclip <noreply@paperclip.ing>

ui/src/components/MarkdownBody.test.tsx

@@ -0,0 +1,31 @@
+// @vitest-environment node
+
+import { describe, expect, it } from "vitest";
+import { renderToStaticMarkup } from "react-dom/server";
+import { ThemeProvider } from "../context/ThemeContext";
+import { MarkdownBody } from "./MarkdownBody";
+
+describe("MarkdownBody", () => {
+  it("renders markdown images without a resolver", () => {
+    const html = renderToStaticMarkup(
+      <ThemeProvider>
+        <MarkdownBody>{"![](/api/attachments/test/content)"}</MarkdownBody>
+      </ThemeProvider>,
+    );
+
+    expect(html).toContain('<img src="/api/attachments/test/content" alt=""/>');
+  });
+
+  it("resolves relative image paths when a resolver is provided", () => {
+    const html = renderToStaticMarkup(
+      <ThemeProvider>
+        <MarkdownBody resolveImageSrc={(src) => `/resolved/${src}`}>
+          {"![Org chart](images/org-chart.png)"}
+        </MarkdownBody>
+      </ThemeProvider>,
+    );
+
+    expect(html).toContain('src="/resolved/images/org-chart.png"');
+    expect(html).toContain('alt="Org chart"');
+  });
+});