Add oauth to supported auth options for WarpStream

[Noel Cothren (noeldevelops)]

Summary of Changes

• Closes Support OAuth for WarpStream connections #3251
• WarpStream now supports OAuth for authentication, so we will allow it in the direct connections form when users choose OAuth type connection.
• Simple change! Since ide-sidecar already fully supports OAuth for direct connections.

Click-testing instructions

1. Try to Create, Edit, Export, Import a Direct Connection with WarpStream selected as the type.
2. Expect SASL/OAUTHBEARER to be available in the Authentication Type dropdown, and expect that the credentials you enter are saved correctly and re-populated on import/edit. (note: it doesn't have to be a working connection to test the form behavior)

Optional: Any additional details or context that should be provided?

Pull request checklist

Please check if your PR fulfills the following (if applicable):

Tests

No new tests because we don't test every possible form combination. We already have playwright tests for the underlying components in the form to verify that the auth options components hold & pass inputs as expected.

Release notes

• Does anything in this PR need to be mentioned in the user-facing CHANGELOG?

[sonarqube-confluent]

Quality Gate passed

Issues
0 New issues
0 Fixed issues
0 Accepted issues

Measures
0 Security Hotspots
100.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube

[Noel Cothren (noeldevelops)]

Stefan Sprenger (@flippingbits) tagging you to confirm, but I think we discussed that this doesn't need a change in ide-sidecar since it already fully supports OAuth for direct connections

[Copilot]

Pull request overview

Enables SASL/OAUTHBEARER as an authentication option for WarpStream in the Direct Connections webview form, aligning the extension UI with WarpStream’s newly documented OAuth support.

Changes:

• Allow "OAuth" in the filtered Kafka auth options when formConnectionType is "WarpStream".
• Add an Unreleased changelog entry documenting the new supported auth option.

Reviewed changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated 1 comment.

File	Description
src/webview/direct-connect-form.ts	Expands WarpStream’s allowed Kafka auth dropdown options to include OAuth.
CHANGELOG.md	Documents the new WarpStream OAuth support in the direct connections form.

[Copilot]

This change adds a new platform-specific auth option (OAuth) for WarpStream, but there’s no automated coverage asserting that the Kafka auth type dropdown includes "OAuth" when formConnectionType is "WarpStream" (and that switching platforms preserves/resets the selected auth type appropriately). Since this webview already has Playwright coverage for other auth/platform combinations, please add a spec that selects WarpStream and verifies the available kafka_cluster.auth_type options include OAuth (and that an invalid previous selection gets coerced to a valid one).