[wangyinz]

Closes #845

Summary

• Measure atomic scaling amplitudes only on the physical intersection of the requested window and datum.
• Preserve the inclusive MsPASS sampling convention: equal endpoints and boundary-touching intersections measure one real sample.
• Reject only truly disjoint intersections with MsPASSError(Invalid) before mutation.
• Compute ensemble mean or median only from live, positive, finite amplitudes.
• Apply the resulting common gain and calibration update to every live member.
• Make the no-eligible-member case an exact no-op.

Maintainer decision

The scale statistic retains the definition used since this function was introduced. This change repairs window intersection and mixed-member handling without redefining amplitude, percentile rank, or ensemble statistics.

Validation

• Rebuilt native Release scale contract: passed
• Rebuilt Python binding scale contract plus adjacent window regressions: 29 passed
• Python byte compilation, formatting, and git diff --check: passed

[codecov]

Codecov Report

❌ Patch coverage is 96.48241% with 7 lines in your changes missing coverage. Please review.
✅ Project coverage is 71.15%. Comparing base (568586b) to head (2868a4e).

Files with missing lines	Patch %	Lines
cxx/test/scale/test_scale_contract.cc	96.13%	4 Missing and 3 partials ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##           master     #929      +/-   ##
==========================================
+ Coverage   70.96%   71.15%   +0.18%     
==========================================
  Files         179      180       +1     
  Lines       35298    35471     +173     
  Branches     2490     2506      +16     
==========================================
+ Hits        25049    25239     +190     
+ Misses       9353     9335      -18     
- Partials      896      897       +1     

☔ 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.