feat(cli): refine default table output and introduce "default" column alias

Simplify the default table view by moving verbose columns to the verbose mode and allow users to explicitly request the default layout using `--columns default`.

crates/irtt-cli/src/cmd/client/output.rs

@@ -27,7 +27,10 @@ impl OutputConfig {
         header: HeaderMode,
         verbose: bool,
     ) -> Result<Self, String> {
-        let default_table_rows = format == OutputFormat::Table && columns.is_none();
+        let uses_default_columns = columns
+            .map(|columns| columns.trim() == "default")
+            .unwrap_or(true);
+        let default_table_rows = format == OutputFormat::Table && uses_default_columns;
         let columns = match columns {
             Some(columns) => parse_columns(columns, format, verbose)?,
             None => default_columns(format, verbose),
@@ -740,18 +743,18 @@ fn default_columns(format: OutputFormat, verbose: bool) -> Vec<Column> {
             let mut columns = vec![
                 Column::Event,
                 Column::Seq,
-                Column::Remote,
                 Column::Rtt,
                 Column::ReceiveDelay,
                 Column::SendDelay,
                 Column::Ipdv,
                 Column::ServerProcessing,
-                Column::ServerReceivedCount,
-                Column::ServerReceivedWindow,
                 Column::Message,
             ];
             if verbose {
                 columns.extend([
+                    Column::Remote,
+                    Column::ServerReceivedCount,
+                    Column::ServerReceivedWindow,
                     Column::RawRttUs,
                     Column::AdjustedRttUs,
                     Column::Bytes,