fix: add uv.lock to recognized lockfiles (#143)

Fixes #137

The LockFilesAssessor was missing uv.lock in its list of recognized
lockfiles. This caused repositories using uv (Python's modern dependency
manager) to incorrectly fail the lock files assessment.

Co-authored-by: claude[bot] <41898282+claude[bot]@users.noreply.github.com>
Co-authored-by: Jeremy Eder <jeremyeder@users.noreply.github.com>

Author: jeremyeder

src/agentready/assessors/stub_assessors.py

@@ -40,6 +40,7 @@ def assess(self, repository: Repository) -> Finding:
             "pnpm-lock.yaml",
             "poetry.lock",
             "Pipfile.lock",
+            "uv.lock",
             "requirements.txt",
             "Cargo.lock",
             "Gemfile.lock",