[PM-36839] Prepare API base Error

[dani-garcia]

🎟️ Tracking

https://bitwarden.atlassian.net/browse/PM-36839

📔 Objective

Prepare the Error type in bitwarden-api-base so it can be merged with the one in bitwarden-core. This requires:

• UniFFI support
• ResponseContent variant as it's own type, rather than inline in the enum, and without a generic type. Also renamed the variant to not have the Error suffix

Once this change is done, we can proceed with merging both error types, which is done on a separate PR as it involves basically every team: #1050

🚨 Breaking Changes

[github-actions]

🤖 Bitwarden Claude Code Review

Overall Assessment: APPROVE

This PR prepares bitwarden-api-base's Error and ResponseContent types to be merged with bitwarden-core::ApiError (tracked in #1050). It adds an optional uniffi feature (with a custom StatusCode type converter and a hand-rolled serde module), pulls ResponseContent out of the enum into a top-level non-generic struct (renaming content → message and dropping entity), and renames the ResponseError variant to Response. The _Phantom(PhantomData<T>, Infallible) variant is a clean way to keep the generic T alive so downstream impl<T> From<Error<T>> for FooError impls continue to compile without unconstrained-type-parameter errors, while remaining unreachable at runtime.

Code Review Details

No new findings. Prior reviewer concerns (StatusCode type erasure, the http-serde dependency, and the breaking impact on bitwarden-user-crypto-management) were addressed in earlier rounds. All downstream callers of the renamed variant/fields (bitwarden-core, bitwarden-auth, bitwarden-user-crypto-management) have been updated, and the new status_code_serializer is covered by three unit tests (serialize, round-trip, invalid value rejection).

[github-actions]

🔍 SDK Breaking Change Detection

SDK Version: ps/PM-36839-prepare-api-base-error (708c16b)

⚠️ If breaking changes are detected, a corresponding pull request addressing them must be ready for merge in the affected client repository.

Client	Status	Details
typescript	✅ No breaking changes detected	Compilation passed with new SDK version - View Details
android	✅ No breaking changes detected	Compilation passed with new SDK version - View Details

---

Breaking change detection uses the build of the SDK from this branch, including any incompatibities pre-existing on or merged into this branch. Check the workflow logs to confirm.
Results update as workflows complete.

[codecov]

Codecov Report

❌ Patch coverage is 95.00000% with 1 line in your changes missing coverage. Please review.
✅ Project coverage is 84.10%. Comparing base (7bca9fc) to head (0d1055f).
⚠️ Report is 1 commits behind head on main.

Files with missing lines	Patch %	Lines
crates/bitwarden-core/src/error.rs	80.00%	1 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #1049      +/-   ##
==========================================
- Coverage   84.10%   84.10%   -0.01%     
==========================================
  Files         446      446              
  Lines       58768    58769       +1     
==========================================
  Hits        49428    49428              
- Misses       9340     9341       +1     

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.

🚀 New features to boost your workflow:

• ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.
• 📦 JS Bundle Analysis: Save yourself from yourself by tracking and limiting bundle sizes in JS merges.

[djsmith85]

Changes are looking great, just one question regarding removing type information.

[djsmith85]

Changes are looking great !

[sonarqubecloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud