- Single configure_logging(verbose) entry point for Python stdlib logging
- Reads PAPERFORGE_LOG_LEVEL env var (default INFO)
- Invalid env var values silently fall back to WARNING
- verbose=True overrides to DEBUG
- Idempotency guard: if handlers already exist, only adjust level
- StreamHandler writes to stderr with LEVEL:name:message format
- get_paperforge_logger() convenience accessor for early-boot use