Format list as an aligned table

The name is what the eye looks for, but it came last, behind a ragged
date column, so nothing lined up. Worse, colorRepoLine rebuilt the line
with strings.Fields and single spaces, which destroyed the alignment ls
had produced -- the output was aligned only when colour was off.

The listing line is now parsed properly instead of being split at the
size field: name, date and size come out as fields, the date is re-padded
to a fixed twelve columns so "Sep 28  2016" and "Jan  3 14:32" agree, and
the name leads in a column sized to the longest entry. Colour decorates
that layout without changing it, which a test now checks by stripping the
escapes and comparing. `list -a` shows archive sizes, which were parsed
and thrown away before.

An empty result says so instead of printing nothing, which was
indistinguishable from a failure, and the count line matches the rest of
mgsh. The pattern now filters on the repository name rather than the
whole listing line: matching the owner or the date was never intended and
`list 2016` quietly did it.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

colors.go

@@ -2,6 +2,7 @@ package main
 
 import (
 	"fmt"
+	"strconv"
 	"strings"
 )
 
@@ -43,17 +44,47 @@ func padRight(s string, n int) string {
 	return s
 }
 
-// colorRepoLine colors a `list` entry: the leading `ls -ltr` date (3 fields) in
-// yellow and the repository name in green.
-func colorRepoLine(s string) string {
-	if !useColor {
-		return s
+// formatRepoList renders the server listing for `list`: the name first, in a
+// column wide enough for the longest one, then the date, and for archives the
+// size. Names come first because that is what the eye scans for; putting the
+// ragged date there instead is what made the old output hard to read.
+//
+// The order is left as it arrives: `ls -ltr` sorts by modification time, and
+// `push` touches the bare repository, so the most recently worked-on project
+// ends up closest to the prompt.
+func formatRepoList(entries []lsEntry, withSize bool) string {
+	width := 0
+	for _, e := range entries {
+		if len(e.name) > width {
+			width = len(e.name)
+		}
 	}
-	parts := strings.Fields(s)
-	if len(parts) >= 4 {
-		date := strings.Join(parts[:3], " ")
-		name := strings.Join(parts[3:], " ")
-		return col(cYellow, date) + "  " + col(cGreen, name)
+	var b strings.Builder
+	for _, e := range entries {
+		fmt.Fprintf(&b, "  %s  %s", col(cGreen, padRight(e.name, width)), col(cYellow, e.date))
+		if withSize {
+			fmt.Fprintf(&b, "  %s", col(cGray, fmt.Sprintf("%7s", humanSize(e.size))))
+		}
+		b.WriteByte('\n')
 	}
-	return col(cGreen, s)
+	return b.String()
+}
+
+// humanSize renders a byte count compactly, the way `ls -h` does: a decimal
+// only while it still carries information, so "3.2M" but "512K".
+func humanSize(n int64) string {
+	const unit = 1024
+	if n < unit {
+		return strconv.FormatInt(n, 10) + "B"
+	}
+	div, exp := int64(unit), 0
+	for v := n / unit; v >= unit && exp < 4; v /= unit {
+		div *= unit
+		exp++
+	}
+	v := float64(n) / float64(div)
+	if v < 10 {
+		return fmt.Sprintf("%.1f%c", v, "KMGTP"[exp])
+	}
+	return fmt.Sprintf("%.0f%c", v, "KMGTP"[exp])
 }