fix(backend): Handle different GitHub token types in OAuth scope check

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

Author: brendan-kellam

CHANGELOG.md

@@ -10,6 +10,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 ### Fixed
 - Fixed issue where opening GitLab file links would result in a 404. [#846](https://github.com/sourcebot-dev/sourcebot/pull/846)
 - Fixed issue where file references in copied chat answers were relative paths instead of full browse URLs. [#847](https://github.com/sourcebot-dev/sourcebot/pull/847)
+- [EE] Fixed OAuth scope validation to handle different GitHub token types (fine-grained PATs, GitHub App tokens) that don't support scope introspection. [#850](https://github.com/sourcebot-dev/sourcebot/pull/850)
 
 ## [4.10.24] - 2026-02-03