**Root cause:**
The autogenerated Dart OpenAPI client (`UsersApi.createProfileImage()`) had two issues:
1. It set `Content-Type: multipart/form-data` without a boundary, which overrode the correct header that Dart's `MultipartRequest` would set (`multipart/form-data; boundary=...`).
2. It added the file to both `mp.fields` and `mp.files`, creating a duplicate text field.
**Result:**
Multer on the server failed to parse the multipart body, so `@UploadedFile()` was `undefined` → accessing `file.path` in `UserService.createProfileImage()` threw → **500 Internal Server Error**.
**Workaround:**
Bypass the autogenerated method in `UserApiRepository.createProfileImage()` and send the multipart request directly using the same `ApiClient` (basePath + auth), ensuring:
- No manual `Content-Type` header (let `MultipartRequest` set it with boundary)
- File only in `mp.files`, not `mp.fields`
- Proper filename fallback
* refactor: user entity
* chore: rebase fixes
* refactor(mobile): move user service to domain
* fix: timeline not visible on album selection page
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Co-authored-by: shenlong-tanwen <139912620+shalong-tanwen@users.noreply.github.com>
