fix(pdf): restore downloads on PDF conversion preset pages (#629)

Adds downloadUrl/originalSize/processedSize to the pdf-to-image route's synchronous response so PDF conversion presets (pdf-to-png, pdf-to-jpg, pdf-to-tiff) satisfy the standard tool-result contract and show their download action again.

Fixes #623

Co-authored-by: EuanTop <euan@mail.bnu.edu.cn>

apps/api/src/openapi.yaml

@@ -2424,6 +2424,15 @@ paths:
                 properties:
                   jobId:
                     type: string
+                  downloadUrl:
+                    type: string
+                    description: URL to download all pages as ZIP
+                  originalSize:
+                    type: integer
+                    description: Input PDF size in bytes
+                  processedSize:
+                    type: integer
+                    description: Output ZIP size in bytes
                   pageCount:
                     type: integer
                     description: Total pages in the PDF

apps/api/src/routes/tools/pdf-to-image.ts

@@ -396,14 +396,18 @@ export function registerPdfToImageRoute(
       await zipDone;
       const zipBuffer = Buffer.concat(zipChunks);
       await putObject(`outputs/${jobId}/${zipFilename}`, zipBuffer);
+      const zipUrl = `/api/v1/download/${jobId}/${encodeURIComponent(zipFilename)}`;
 
       return reply.send({
         jobId,
+        downloadUrl: zipUrl,
+        originalSize: fileBuffer.length,
+        processedSize: zipBuffer.length,
         pageCount: totalPages,
         selectedPages,
         format: settings.format,
         pages,
-        zipUrl: `/api/v1/download/${jobId}/${encodeURIComponent(zipFilename)}`,
+        zipUrl,
         zipSize: zipBuffer.length,
       });
     } catch (err) {