fix: include image decryption response in reader canvas data

frontend/src/pages/Reader.tsx

@@ -114,27 +114,29 @@ export default function Reader() {
       images: LetterImageData[],
       encrypted_dek: string,
       cryptoUtils: CryptoUtils,
-    ) => {
-      if (!images?.length) return;
+    ): Promise<CanvasJSON> => {
+      if (!images?.length) return canvasData;
       const isShared = !!sharingKey;
       try {
         if (isShared) {
-          await decryptCanvasImagesWithSharingKey(
-            canvasData,
-            images,
-            sharingKey,
-            cryptoUtils,
-          );
-        } else {
-          await decryptCanvasImages(
-            canvasData,
-            images,
-            encrypted_dek,
-            // biome-ignore lint/style/noNonNullAssertion: masterKey is guaranteed to be non-null here as isDecryptionKeyAvailable is true
-            masterKey!,
-            cryptoUtils,
-          );
+          const { canvasDataWithDecryptedImages } =
+            await decryptCanvasImagesWithSharingKey(
+              canvasData,
+              images,
+              sharingKey,
+              cryptoUtils,
+            );
+          return canvasDataWithDecryptedImages;
         }
+        const { canvasDataWithDecryptedImages } = await decryptCanvasImages(
+          canvasData,
+          images,
+          encrypted_dek,
+          // biome-ignore lint/style/noNonNullAssertion: masterKey is guaranteed to be non-null here as isDecryptionKeyAvailable is true
+          masterKey!,
+          cryptoUtils,
+        );
+        return canvasDataWithDecryptedImages;
       } catch (err) {
         setLogTrace({
           message:
@@ -142,6 +144,7 @@ export default function Reader() {
           log: err instanceof Error ? err.message : "Unknown error",
           type: "WARN",
         });
+        return canvasData;
       }
     };
 
@@ -187,8 +190,13 @@ export default function Reader() {
           );
 
       const canvasData: CanvasJSON = JSON.parse(decryptedContent);
-      await decryptImages(canvasData, images, encrypted_dek, cryptoUtils);
-      setDecryptedCanvasData(canvasData);
+      const decryptedCanvasData = await decryptImages(
+        canvasData,
+        images,
+        encrypted_dek,
+        cryptoUtils,
+      );
+      setDecryptedCanvasData(decryptedCanvasData);
     };
 
     const processLetterData = async (data: LetterResponseData) => {