- Add --log-format flag (text/json) and --verbosity flag (debug/info/warn/error)
- Replace all log.Printf with slog.Info/Debug/Warn with structured key-value attrs
- Replace all log.Fatalf with slog.Error + os.Exit(1)
- Convert gitea/client.go warnings to slog.Warn
- Add comprehensive tests for logger initialization and level filtering
Closes#23
Partially addresses #32