docs(repo): add scientific computing background note

[stacknil]

Summary

• add a one-page note on why scientific-computing background helps repository review style
• keep the note limited to reproducibility, data pipeline, and uncertainty boundary
• link the note from README/reviewer brief and add reviewer-route validation, including forbidden domain-identity terms

Validation

• python scripts\validate-reviewer-routes.py
• python -m py_compile scripts\validate-reviewer-routes.py
• python -m pytest
• git diff --check