[desktop] Fix OOM on large library imports (#3847)

It is hard for me to be certain, but I feel this should resolve the
sporadic OOMs that have been reported when uploading large libraries.

- https://github.com/ente-io/ente/issues/2500 
- https://github.com/ente-io/ente/discussions/3420

There are two fixes here:

1. First one is a inefficient array concat in our code. This was not
incorrect per se, but it did lead to an allocation pattern that caused
V8's GC to crash the renderer with OOMs.

2. But even after the first fix, I was able to sometimes reproduce OOMs.
I added a lot of instrumentation (I've cherry-committed some of it to
git history for future reference when debugging similar issues), but I
couldn't spot any abnormal allocation patterns during uploads. Out of
ideas, I started imagining it was a Chromium issue, and on a whim, I
updated Electron 30 => 33 (something I needed to do anyway, as part of
regular app dependency updates). That apparently has resolved the
remaining OOMs.

With these changes, I've not been able to reproduce a crash even after
bumping up the parallel upload count from 4 to 12. I've let the parallel
upload count be at the existing 4 for now, but if indeed we stop getting
field reports of OOM crashes after this is released, we can increase
that too in the future.

desktop/package.json

@@ -48,7 +48,7 @@
         "ajv": "^8.17.1",
         "concurrently": "^8.2.2",
         "cross-env": "^7.0.3",
-        "electron": "^30.4.0",
+        "electron": "^33.0.2",
         "electron-builder": "^25.0.5",
         "eslint": "^9",
         "prettier": "^3.3.3",

desktop/yarn.lock

@@ -1282,10 +1282,10 @@ electron-updater@^6.3.4:
     semver "^7.6.3"
     tiny-typed-emitter "^2.1.0"
 
-electron@^30.4.0:
-  version "30.4.0"
-  resolved "https://registry.yarnpkg.com/electron/-/electron-30.4.0.tgz#66641a644059147f0e597e49999599e23dcdbfe3"
-  integrity sha512-ric3KLPQ9anXYjtTDkj5NbEcXZqRUwqxrxTviIjLdMdHqd5O+hkSHEzXgbSJUOt+7uw+zZuybn9+IM9y7iEpqg==
+electron@^33.0.2:
+  version "33.0.2"
+  resolved "https://registry.yarnpkg.com/electron/-/electron-33.0.2.tgz#db31b105bf0edd7c8600dfb70c2dfc214e3789f1"
+  integrity sha512-C2WksfP0COsMHbYXSJG68j6S3TjuGDrw/YT42B526yXalIlNQZ2GeAYKryg6AEMkIp3p8TUfDRD0+HyiyCt/nw==
   dependencies:
     "@electron/get" "^2.0.0"
     "@types/node" "^20.9.0"

web/apps/photos/src/services/upload/upload-service.ts

@@ -37,6 +37,7 @@ import {
 } from "@/new/photos/services/upload/types";
 import { detectFileTypeInfoFromChunk } from "@/new/photos/utils/detect-type";
 import { readStream } from "@/new/photos/utils/native-stream";
+import { mergeUint8Arrays } from "@/utils/array";
 import { ensure, ensureInteger, ensureNumber } from "@/utils/ensure";
 import { CustomError, handleUploadError } from "@ente/shared/error";
 import { addToCollection } from "services/collectionService";
@@ -1573,9 +1574,7 @@ async function combineChunksToFormUploadPart(
         if (done) {
             break;
         }
-        for (let index = 0; index < chunk.length; index++) {
-            combinedChunks.push(chunk[index]);
-        }
+        combinedChunks.push(chunk);
     }
-    return Uint8Array.from(combinedChunks);
+    return mergeUint8Arrays(combinedChunks);
 }