* implement --silent flag to control output verbosity
* update error handling to restore stderr after silent mode
* enhance progress reporting in PostgreSQL reader
Previously the version banner only printed via PersistentPreRun, which
Cobra skips for --help and bare invocations. It now prints from main()
before Cobra parses anything, so it's the first line for every command.
Suppressible with --no-version; skipped for the version subcommand to
avoid duplicating its own output.