fix: Picker frame was one line taller than the terminal, hiding the filter line

internal/picker/view.go

@@ -57,11 +57,11 @@ func (m Model) View() tea.View {
 
 	list := m.listView(t, groups, rows, lay, now)
 	if lay.ShowPreview {
-		// The preview column is joined under a matching blank line so its
-		// box's top border lands on the list's first row, not on the
-		// filter line above.
-		right := "\n" + m.previewView(t, rows, lay, now)
-		b.WriteString(lipgloss.JoinHorizontal(lipgloss.Top, list, " ", right))
+		// The preview box is exactly ListHeight lines tall (lipgloss v2
+		// counts the border in Height), so joining it at the top keeps
+		// the frame at the terminal height: one taller and the renderer
+		// drops the filter line and repaints every tick.
+		b.WriteString(lipgloss.JoinHorizontal(lipgloss.Top, list, " ", m.previewView(t, rows, lay, now)))
 	} else {
 		b.WriteString(list)
 	}
@@ -204,7 +204,8 @@ func (m Model) previewView(t theme, rows []match, lay Layout, now time.Time) str
 		BorderForeground(t.rule).
 		Padding(0, 1).
 		Width(lay.PreviewWidth).
-		Height(lay.ListHeight)
+		Height(lay.ListHeight).
+		MaxHeight(lay.ListHeight) // Height is a minimum; a tall body must not grow the box
 	return box.Render(body.String())
 }
 

internal/picker/view_test.go

@@ -130,3 +130,25 @@ func TestModel_View_RowsShareEqualWidth(t *testing.T) {
 		}
 	}
 }
+
+// TestModel_View_FrameMatchesTerminalHeight pins the frame to exactly the
+// terminal height, with and without the preview pane. One line taller and
+// Bubble Tea's inline renderer drops the filter line off the top.
+func TestModel_View_FrameMatchesTerminalHeight(t *testing.T) {
+	rows := manyRows(11)
+	for _, width := range []int{110, 45} {
+		for _, height := range []int{40, 30, 24, 14, 9} {
+			m := picker.NewModel(rows, noopStatus, picker.Options{})
+			next, _ := m.Update(tea.WindowSizeMsg{Width: width, Height: height})
+			m = next.(picker.Model)
+
+			lines := strings.Split(m.View().Content, "\n")
+			if len(lines) != height {
+				t.Errorf("View() at %dx%d produced %d lines, want exactly %d", width, height, len(lines), height)
+			}
+			if !strings.Contains(lines[0], "type to filter") {
+				t.Errorf("View() at %dx%d: first line %q is not the filter line", width, height, lines[0])
+			}
+		}
+	}
+}