refactor: Use Status().Patch() for git status updates in chain handle…

[SergK]

…rs (#227)

Replace Status().Update() with Status().Patch() to reduce conflicts during sequential git status updates in chain handlers. Patch uses server-side merge semantics, only conflicting when the same field is modified concurrently.

Changes:

• Add updateGitStatusWithPatch helper function with idempotency check
• Update PutProject, PutGitLabCIConfig, PutDeployConfigs handlers
• Add comprehensive unit tests for sequential update scenarios

Pull Request Template

Description

Please include a summary of the change and why it is needed.

Fixes #227

Type of change

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Enhancement (non-breaking change which improves an existing feature or documentation)
• Breaking change (fix or feature that would cause existing functionality not to work as expected)

Checklist:

• I have performed a self-review of my code
• I have commented on my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• My changes generate no new warnings
• I have added tests that prove my fix is effective or that my feature works
• New and existing unit tests pass locally with my changes
• Pull Request contains one commit. I squash my commits.