feat: add header with version and fix layout calculations

internal/tui/model.go

@@ -212,7 +212,13 @@ func (m *Model) updateLayout() {
 
 	rightWidth := 42
 	leftWidth := m.width - rightWidth - 3
-	chatHeight := m.height - 5
+	headerHeight := 3
+	mainHeight := m.height - headerHeight - 1
+	inputHeight := 5
+	chatHeight := mainHeight - inputHeight
+	if chatHeight < 10 {
+		chatHeight = 10
+	}
 
 	m.textarea.SetWidth(leftWidth)
 	m.viewport.Width = leftWidth
@@ -261,7 +267,15 @@ func (m Model) View() string {
 
 	rightWidth := 42
 	leftWidth := m.width - rightWidth - 3
-	chatHeight := m.height - 5
+	headerHeight := 3
+	mainHeight := m.height - headerHeight - 1
+	inputHeight := 5
+	chatHeight := mainHeight - inputHeight
+	if chatHeight < 10 {
+		chatHeight = 10
+	}
+
+	header := m.renderHeader()
 
 	chatBox := boxStyle.Width(leftWidth).Height(chatHeight).Render(m.viewport.View())
 	inputBox := boxStyle.Width(leftWidth).Render(m.textarea.View())
@@ -272,7 +286,7 @@ func (m Model) View() string {
 
 	statsHeight := lipgloss.Height(stats)
 	agentsHeight := lipgloss.Height(agents)
-	remainingHeight := m.height - statsHeight - agentsHeight - 2
+	remainingHeight := mainHeight - statsHeight - agentsHeight - 2
 	if remainingHeight < 3 {
 		remainingHeight = 3
 	}
@@ -284,7 +298,19 @@ func (m Model) View() string {
 		leftPanel = lipgloss.JoinVertical(lipgloss.Left, leftPanel, processingStyle.Render("Processing..."))
 	}
 
-	return lipgloss.JoinHorizontal(lipgloss.Top, leftPanel, rightPanel)
+	body := lipgloss.JoinHorizontal(lipgloss.Top, leftPanel, rightPanel)
+	return lipgloss.JoinVertical(lipgloss.Left, header, body)
+}
+
+func (m Model) renderHeader() string {
+	version := "v0.1.0"
+	title := titleStyle.Render("orca.agent ") + mutedStyle.Render(version)
+	return lipgloss.NewStyle().
+		Width(m.width).
+		Height(1).
+		Padding(0, 1).
+		Background(lipgloss.Color(colors.bg)).
+		Render(title)
 }
 
 func (m Model) renderStats() string {