Enhance file download handling and format validation in htmlDocumentConverter

main.js

@@ -225,9 +225,22 @@ electron.ipcMain.on("file_submit", async (event, args) => {
     }
 })
 
-electron.ipcMain.on("file_download", async() => {
-    await mapFunctions.get("htmlDocumentConverter").convert({inputPath:globalFinalHtmlPath, format: globalArgs.document.outputType, showDialog: true});
-})
+ipcMain.handle("file_download", async () => {
+  try {
+    const format = globalArgs.document.outputType.replace('.', '').toLowerCase();
+
+    return await mapFunctions
+      .get("htmlDocumentConverter")
+      .convert({
+        inputPath: globalFinalHtmlPath,
+        format,
+        showDialog: true
+      });
+  } catch (err) {
+    console.error("Download failed:", err);
+    throw err;
+  }
+});
 
 electron.ipcMain.on("speaker_submit", async() => {
     console.log("\n\n\nJa also hier kam was an \n\n\n");