[zhangzhenghao]

Summary

• Remove the unused common/ann package.
• Remove MatrixFactorizationItems, its distance helper, and its obsolete test.
• Preserve MatrixFactorizationUsers and its existing test; production collaborative filtering uses vector storage.

Verification

• go test ./logics passed.
• git diff --check passed.
• Repository search found no remaining common/ann or MatrixFactorizationItems references.
• Whole-repository compile check (go test ./... -run '^$') timed out locally; not confirmed passing.

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 78.03%. Comparing base (44791ec) to head (6f66622).

Additional details and impacted files

@@            Coverage Diff             @@
##           master    #1422      +/-   ##
==========================================
- Coverage   78.37%   78.03%   -0.34%     
==========================================
  Files          93       91       -2     
  Lines       16730    16427     -303     
==========================================
- Hits        13112    12819     -293     
+ Misses       3618     3608      -10     

☔ View full report in Codecov by Harness.
📢 Have feedback on the report? Share it here.

🚀 New features to boost your workflow:

• ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.