fix: allow PDF uploads in backend OCR controller and service (refs #182)

The backend SUPPORTED_IMAGE_TYPES set excluded application/pdf, returning
415 before the request ever reached the OCR microservice. Added PDF to
the allowed types in both controller and service validation layers.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

backend/src/features/ocr/api/ocr.controller.ts

@@ -15,12 +15,13 @@ const SUPPORTED_TYPES = new Set([
   'application/pdf',
 ]);
 
-/** Image-only MIME types for receipt extraction (no PDF) */
+/** Image-only MIME types for receipt extraction */
 const SUPPORTED_IMAGE_TYPES = new Set([
   'image/jpeg',
   'image/png',
   'image/heic',
   'image/heif',
+  'application/pdf',
 ]);
 
 export class OcrController {
@@ -268,7 +269,7 @@ export class OcrController {
       });
       return reply.code(415).send({
         error: 'Unsupported Media Type',
-        message: `Unsupported file type: ${contentType}. Supported: JPEG, PNG, HEIC`,
+        message: `Unsupported file type: ${contentType}. Supported: JPEG, PNG, HEIC, PDF`,
       });
     }
 
@@ -380,7 +381,7 @@ export class OcrController {
       });
       return reply.code(415).send({
         error: 'Unsupported Media Type',
-        message: `Unsupported file type: ${contentType}. Supported: JPEG, PNG, HEIC`,
+        message: `Unsupported file type: ${contentType}. Supported: JPEG, PNG, HEIC, PDF`,
       });
     }
 

backend/src/features/ocr/domain/ocr.service.ts

@@ -31,12 +31,13 @@ const SUPPORTED_TYPES = new Set([
   'application/pdf',
 ]);
 
-/** Image-only MIME types for receipt extraction (no PDF) */
+/** MIME types for receipt extraction */
 const SUPPORTED_IMAGE_TYPES = new Set([
   'image/jpeg',
   'image/png',
   'image/heic',
   'image/heif',
+  'application/pdf',
 ]);
 
 /**