Add logging functions to lib/common.sh for consistent output formatting:
- log_info(): Standard informational messages with [INFO] prefix
- log_warn(): Warning messages to stderr with [WARN] prefix
- log_error(): Error messages to stderr with [ERROR] prefix
- log_step(): Section headers with visual separators
Update upgrade.sh to use these functions throughout, replacing ad-hoc
echo statements. This provides:
- Consistent visual formatting across all scripts
- Clear distinction between info, warnings and errors
- Errors properly sent to stderr
- Easier log parsing and filtering
Also removed redundant '|| exit 1' statements since set -e handles
command failures automatically.
d3f0998036