* fix(doctor): handle 's' status in combined git flags
Problem:
- Git status detection failed when 's' was combined with other flags
- Branch synchronization checks produced incorrect results due to missing flag parsing
Solution:
- Update detection logic to correctly identify the 's' status within combined flag strings
Impact:
- Ensures branch synchronization state is accurately reported during doctor checks
* test(doctor): add unit tests for git flag parsing
- Extract git flag parsing logic into parseGitLsFilesFlag helper
- Add unit tests for git flag parsing logic
Coverage: Git flag parsing in sync_branch.go