[LacerdaTraderCode]

Closes #3
Closes #1

What changed

Brings the 30 commits of chore/professional-standard into main, which never had them:

• CI: workflow with ruff check . && ruff format --check . and pytest -v; CI badge in the README.
• Config: pyproject.toml (ruff: line length 100, rules E, F, I, UP, RUF), pytest.ini, requirements-dev.txt; scripts becomes an importable package.
• Refactors of the 8 scripts (behavior-relevant, not only style): translated to English; logic separated from the CLI; functions now return results or summaries (bulk_rename, excel_merger, folder_backup, log_analyzer); bulk_rename guards against name collisions; email_sender reports missing configuration; system_monitor loop is bounded so it can be tested.
• Tests: 8 test files covering every script.
• README: CI badge and a development section (+16 lines, no deletions).

How it was validated

CI on this PR: Lint (check and format) and pytest -v ran and passed, with nothing skipped: 81 tests passed (run #39022680195). No check was disabled and no test was weakened by this PR.

Notes

• PR ci: add GitHub Actions workflow (lint, compile, tests) #2 (ci/github-actions) is superseded by this one; it is closed only with the owner's approval.
• The README addition does not remove the English translation already on main.