fix: details load once the cursor rests, and moving on cancels them

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

internal/ui/app/fields.go

@@ -30,7 +30,8 @@ type groupsMsg struct {
 }
 
 // A vault's, scope's or file's details beyond its listing load once a
-// session, the first time it's shown, and again with refresh.
+// session, when the cursor rests on it, and again with refresh. They're
+// extra: moving on cancels the load, and search never waits for them.
 type detailsState struct {
 	attrs   []provider.Attr
 	err     error
@@ -38,6 +39,7 @@ type detailsState struct {
 }
 
 type detailsMsg struct {
+	req   int
 	key   string
 	attrs []provider.Attr
 	err   error
@@ -211,14 +213,22 @@ func (m *Model) loadDetails(c provider.Container) tea.Cmd {
 	if _, seen := m.details[key]; !ok || seen {
 		return nil
 	}
-	m.details[key] = detailsState{loading: true}
-	timeout := m.timeout
-	return func() tea.Msg {
-		ctx, cancel := context.WithTimeout(context.Background(), timeout)
-		defer cancel()
-		attrs, err := d.Details(ctx, c)
-		return detailsMsg{key: key, attrs: attrs, err: err}
+	// One at a time: the previous one, if it's still loading, is
+	// cancelled and forgotten, to load when it's shown again.
+	for k, st := range m.details {
+		if st.loading {
+			delete(m.details, k)
+		}
 	}
+	m.details[key] = detailsState{loading: true}
+	ctx, req := m.begin(slotDetails)
+	return m.settled(ctx, func() tea.Msg {
+		attrs, err := d.Details(ctx, c)
+		if ctx.Err() != nil {
+			err = ctx.Err()
+		}
+		return detailsMsg{req: req, key: key, attrs: attrs, err: err}
+	})
 }
 
 // problemFields show why an account has nothing to show, wrapped to the