fix: align the result tables and size the IP column to content

- compute the IP column width from the widest address instead of a
  fixed 39 (which left a big gap for IPv4-only output)
- left-align the latency and speed columns so the header labels line up
  with their values, instead of right-aligning into a wide field
- keep the colored speed as the last column so it needs no width padding

src/report.rs

@@ -179,10 +179,11 @@ pub(crate) fn read_export_rows(path: &Path) -> Result<Vec<ExportRow>> {
 pub(crate) fn print_table<T: Ranked>(results: &[T]) {
     eprintln!();
     eprintln!("{}", style(format!("  Fastest {} IPs", results.len())).bold().underlined());
-    eprintln!("  {:>3}  {:<39}  {:>9}", "#", "IP", "Latency");
+    let ip_w = ip_col_width(results.iter().map(|r| r.ip()));
+    eprintln!("  {:>3}  {:<ip_w$}  {}", "#", "IP", "Latency");
     for (i, r) in results.iter().enumerate() {
         let ms = r.latency().as_secs_f64() * 1000.0;
-        let latency = format!("{ms:>6.1} ms");
+        let latency = format!("{ms:.1} ms");
         let colored = if ms < 150.0 {
             style(latency).green()
         } else if ms < 250.0 {
@@ -190,18 +191,25 @@ pub(crate) fn print_table<T: Ranked>(results: &[T]) {
         } else {
             style(latency).red()
         };
-        eprintln!("  {:>3}  {:<39}  {}", i + 1, r.ip().to_string(), colored);
+        eprintln!("  {:>3}  {:<ip_w$}  {}", i + 1, r.ip().to_string(), colored);
     }
     eprintln!();
 }
 
+/// Width for the IP column: the widest address present, but at least "IP".
+fn ip_col_width(ips: impl Iterator<Item = IpAddr>) -> usize {
+    ips.map(|ip| ip.to_string().len()).max().unwrap_or(0).max(2)
+}
+
 /// Speed-stage table: IP, latency, speed.
 pub(crate) fn print_speed_table(results: &[speed::SpeedResult]) {
     eprintln!();
     eprintln!("{}", style(format!("  Top {} nodes", results.len())).bold().underlined());
-    eprintln!("  {:>3}  {:<39}  {:>9}  {:>10}", "#", "IP", "Latency", "Speed");
+    let ip_w = ip_col_width(results.iter().map(|r| r.ip));
+    eprintln!("  {:>3}  {:<ip_w$}  {:<9}  {}", "#", "IP", "Latency", "Speed");
     for (i, r) in results.iter().enumerate() {
-        let ms = r.latency.as_secs_f64() * 1000.0;
+        let latency = format!("{:.0} ms", r.latency.as_secs_f64() * 1000.0);
+        // Speed is the last column, so it can stay colored without padding.
         let speed = format!("{:.2} MB/s", r.speed_mbs);
         let colored = if r.speed_mbs >= 2.5 {
             style(speed).green()
@@ -210,7 +218,7 @@ pub(crate) fn print_speed_table(results: &[speed::SpeedResult]) {
         } else {
             style(speed).red()
         };
-        eprintln!("  {:>3}  {:<39}  {:>6.0} ms  {}", i + 1, r.ip.to_string(), ms, colored);
+        eprintln!("  {:>3}  {:<ip_w$}  {:<9}  {}", i + 1, r.ip.to_string(), latency, colored);
     }
     eprintln!();
 }