feat : adding dialog to choose language

lib/guides/image-export.test.tsx

@@ -17,6 +17,8 @@ describe("image export controls", () => {
     expect(html).toContain("ส่งออกภาพโดยไม่รวมโน้ต");
     expect(html).toContain("ไทย");
     expect(html).toContain("English");
+    expect(html).toContain('data-language-flag="th"');
+    expect(html).toContain('data-language-flag="en"');
     expect(html.match(/<button\b/gu)).toHaveLength(4);
   });
 
@@ -27,6 +29,22 @@ describe("image export controls", () => {
     expect(html.match(/<button\b/gu)).toHaveLength(3);
   });
 
+  it("hides the persistent language chooser when language is prompted on export", () => {
+    const html = renderToStaticMarkup(
+      <GuideImageExport
+        fileName="guide.png"
+        allowWithoutNotes={false}
+        showLanguageSelector={false}
+        promptForLanguage
+      >
+        Content
+      </GuideImageExport>,
+    );
+    expect(html).not.toContain("ภาษาในภาพส่งออก");
+    expect(html).not.toContain("English");
+    expect(html.match(/<button\b/gu)).toHaveLength(1);
+  });
+
   it("disables both modes when an export selection is empty", () => {
     const html = renderToStaticMarkup(<GuideImageExport fileName="guide.png" disabled>No sections</GuideImageExport>);
     expect(html.match(/\sdisabled=""/gu)).toHaveLength(2);