feat: the right pane describes what's selected in the pane you're in

Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>

internal/ui/panes/fields.go

@@ -15,13 +15,14 @@ import (
 // have Detail, for revealing and versions.
 type Fields struct {
 	List[Field]
+	shown bool
 }
 
 // Field is a row: a value under a label. Info rows (loading, errors)
-// can't be copied.
+// can't be copied; Err ones are errors.
 type Field struct {
 	Label, Value string
-	Info         bool
+	Info, Err    bool
 }
 
 func NewFields() Fields {
@@ -32,30 +33,35 @@ func NewFields() Fields {
 		FilterExtra: func(f Field) string { return f.Label },
 		Render: func(st styles.Styles, f Field, width int) string {
 			value := f.Value
-			if f.Info {
+			switch {
+			case f.Err:
+				value = st.Error.Render(value)
+			case f.Info:
 				value = st.Muted.Render(value)
 			}
 			return ansi.Truncate(st.Label.Render(fmt.Sprintf("%-10s", f.Label))+" "+value, width, "…")
 		},
 	})
 	l.Empty = "nothing to show"
-	return Fields{l}
+	return Fields{List: l}
 }
 
-// Set shows fields under title. Another title (another account or vault)
-// starts over, without a filter.
-func (s *Fields) Set(title string, fields []Field) {
+// Show shows fields under title, instead of the secret pane. Another
+// title (another account or vault) starts over, without a filter.
+func (s *Fields) Show(title string, fields []Field) {
 	if title != s.Title {
 		s.Reset()
 		s.Title = title
 	}
-	if len(fields) > 0 || len(s.Items()) > 0 {
-		s.SetItems(fields)
-	}
+	s.shown = true
+	s.SetItems(fields)
 }
 
-// Shown reports whether there's anything to show.
-func (s Fields) Shown() bool { return len(s.Items()) > 0 }
+// Hide gives the fourth pane back to the secret pane.
+func (s *Fields) Hide() { s.shown = false }
+
+// Shown reports whether the fourth pane shows Fields.
+func (s Fields) Shown() bool { return s.shown }
 
 // Selected is the field under the cursor, unless it's an info row.
 func (s Fields) Selected() (Field, bool) {