refactor(middleware): clamp remaining tokens with max

[elonfliter]

RateLimiterMemoryStore clamps the floored token count before writing X-RateLimit-Remaining.

Use the built-in max function for the lower bound, preserving the existing zero-floor behavior with less branching.

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 95.73%. Comparing base (dcb05f0) to head (1d718b6).
⚠️ Report is 11 commits behind head on master.

Additional details and impacted files

@@            Coverage Diff             @@
##           master    #3076      +/-   ##
==========================================
+ Coverage   93.34%   95.73%   +2.38%     
==========================================
  Files          43       44       +1     
  Lines        4735     4033     -702     
==========================================
- Hits         4420     3861     -559     
+ Misses        192      172      -20     
+ Partials      123        0     -123     

☔ 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.

[aldas]

LGTM