feat: mark lean TUI prompts in terminal scrollback

pkg/leantui/leantui.go

@@ -67,6 +67,7 @@ func Run(ctx context.Context, cfg Config) error {
 	}
 	m.status.Branch = branchWatcher.Current()
 	m.commitWelcome()
+	m.loadInitialSessionTranscript()
 	m.refreshCommands(loopCtx)
 
 	keys := make(chan ui.Key, 64)

pkg/leantui/ui/render.go

@@ -9,6 +9,11 @@ import (
 	"github.com/docker/docker-agent/pkg/tui/styles"
 )
 
+const (
+	seqPromptStart = "\x1b]133;A;redraw=0\x07"
+	seqOutputStart = "\x1b]133;C\x07"
+)
+
 // RenderUserLines renders a submitted user message as committed scrollback,
 // echoing it with the same prompt marker used by the input box.
 func RenderUserLines(text string, width int) []string {
@@ -19,7 +24,11 @@ func RenderUserLines(text string, width int) []string {
 	innerWidth := max(width-boxStyle.GetHorizontalFrameSize(), 1)
 	textStyle := lipgloss.NewStyle().Foreground(styles.AgentBadgeFg)
 	content := strings.Join(RenderUserLinesWith(text, innerWidth, textStyle.Bold(true), textStyle), "\n")
-	return splitRenderedLines(styles.RenderComposite(boxStyle, content), width)
+	lines := splitRenderedLines(styles.RenderComposite(boxStyle, content), width)
+	if len(lines) > 0 {
+		lines[0] = seqPromptStart + lines[0] + seqOutputStart
+	}
+	return lines
 }
 
 func RenderPendingUserLines(msg PendingUserMessage, width int) []string {

pkg/leantui/ui/render_test.go

@@ -1,6 +1,7 @@
 package ui
 
 import (
+	"strings"
 	"testing"
 
 	"github.com/stretchr/testify/assert"
@@ -9,6 +10,18 @@ import (
 	"github.com/docker/docker-agent/pkg/tui/styles"
 )
 
+func TestRenderUserLinesMarksPromptStart(t *testing.T) {
+	t.Parallel()
+
+	lines := RenderUserLines("jump back here", 24)
+	require.NotEmpty(t, lines)
+	assert.True(t, strings.HasPrefix(lines[0], seqPromptStart))
+	assert.True(t, strings.HasSuffix(lines[0], seqOutputStart))
+	assert.Equal(t, 1, strings.Count(strings.Join(lines, ""), seqPromptStart))
+	assert.Equal(t, 1, strings.Count(strings.Join(lines, ""), seqOutputStart))
+	assert.Equal(t, 24, DisplayWidth(lines[0]))
+}
+
 func TestRenderUserLinesUsesDistinctFullWidthBackground(t *testing.T) {
 	t.Parallel()
 

pkg/leantui/update.go

@@ -434,6 +434,13 @@ func (m *model) resumeSession(ctx context.Context, sessionID string) {
 	m.addNotice("", "Resumed session: "+title, ui.StMuted())
 }
 
+func (m *model) loadInitialSessionTranscript() {
+	if m.app == nil || m.app.Session() == nil || len(m.app.Session().OwnMessages()) == 0 {
+		return
+	}
+	m.loadSessionTranscript(m.app.Session())
+}
+
 func (m *model) loadSessionTranscript(sess *session.Session) {
 	storedMessages := sess.OwnMessages()
 	toolResults := make(map[string]chat.Message)

pkg/leantui/update_test.go

@@ -234,6 +234,27 @@ func TestSessionsCommandListsCurrentDirectoryAndResumesSelection(t *testing.T) {
 	assert.NotContains(t, transcript, "Other directory")
 }
 
+func TestLoadInitialSessionTranscriptMarksRestoredUserMessages(t *testing.T) {
+	t.Parallel()
+
+	sess := session.New()
+	sess.AddMessage(session.UserMessage("restored question"))
+	sess.AddMessage(session.NewAgentMessage("coder", &chat.Message{
+		Role:    chat.MessageRoleAssistant,
+		Content: "restored answer",
+	}))
+
+	m := bareModel(80)
+	m.app = app.New(t.Context(), &cycleThinkingRuntime{}, sess)
+	m.sessionState = service.NewSessionState(sess)
+	m.loadInitialSessionTranscript()
+
+	transcript := strings.Join(m.screen.Transcript.Lines(80, 0, false, m.sessionState, nil), "\n")
+	assert.Contains(t, transcript, "\x1b]133;A;redraw=0\x07")
+	assert.Contains(t, transcript, "restored question")
+	assert.Contains(t, transcript, "restored answer")
+}
+
 func TestLoadSessionTranscriptRestoresToolCalls(t *testing.T) {
 	t.Parallel()
 	sess := session.New()