Adjust logging for development and production

[caydyan]

/claim #23

Summary

• Configure backend logging level from environment variables instead of always using DEBUG.
• Add APP_ENV=development to .env.example; development-like values keep DEBUG logging while production-like values use INFO.
• Gate frontend debug console.log output behind localhost or window.DEVCONTAINER_DEBUG_LOGS === true, while preserving error logging.
• Add focused unit coverage for the logging-level helper.

Tests

python3 -m unittest tests/test_logging_helpers.py
python3 -m compileall helpers main.py tests/test_logging_helpers.py
git diff --check

Repository note

Algora links this bounty to daytonaio/devcontainer-generator#23, but that GitHub repo path currently returns 404/disabled issues. This PR targets nibzard/devcontainer-generator, matching the existing claim PR pattern in this repo.