新增: HISTORY 历史会话功能

三栏布局(目录/会话/详情), 扫描 ~/.claude/projects JSONL,
支持 resume 会话, 缓存增量更新, 代码审查问题修复

internal/app.go

@@ -26,6 +26,7 @@ type Model struct {
 	width       int
 	height      int
 	launched    string
+	history     HistoryState
 }
 
 func NewModel() *Model {
@@ -39,28 +40,81 @@ func (m *Model) Init() tea.Cmd {
 	return nil
 }
 
+// totalTabs 包含 HISTORY 的总 Tab 数
+func (m *Model) totalTabs() int {
+	return len(Groups) + 1
+}
+
 func (m *Model) Update(msg tea.Msg) (tea.Model, tea.Cmd) {
 	switch msg := msg.(type) {
 	case tea.KeyPressMsg:
-		s := msg.String()
+		return m.handleKey(msg.String())
+	case tea.WindowSizeMsg:
+		m.width = msg.Width
+		m.height = msg.Height
+	case ScanCompleteMsg:
+		m.history.Projects = msg.Projects
+		m.history.Loaded = true
+		m.history.Scanning = false
+		return m, nil
+	}
+	return m, nil
+}
+
+// --- 按键分发 ---
+
+func (m *Model) handleKey(s string) (*Model, tea.Cmd) {
+	// 全局按键
 	switch s {
 	case "q", "ctrl+c":
 		return m, tea.Quit
-		case "tab", "right", "l":
-			m.activeGroup = (m.activeGroup + 1) % len(Groups)
-			m.cursor = 0
-			m.inputBuf = ""
-		case "shift+tab", "left", "h":
-			m.activeGroup = (m.activeGroup - 1 + len(Groups)) % len(Groups)
-			m.cursor = 0
-			m.inputBuf = ""
-		case "1", "2", "3", "4":
+	}
+
+	// 数字键跳转 Tab
+	if len(s) == 1 && s[0] >= '1' && s[0] <= '9' {
 		idx, _ := strconv.Atoi(s)
-			if idx <= len(Groups) {
+		if idx <= m.totalTabs() {
 			m.activeGroup = idx - 1
 			m.cursor = 0
 			m.inputBuf = ""
+			return m, m.onTabSwitch()
 		}
+	}
+
+	// HISTORY Tab: tab/left/right 用于面板切换
+	if m.IsHistoryTab() {
+		return m.handleHistoryKey(s)
+	}
+
+	// Workspace Tab 按键
+	switch s {
+	case "tab", "right", "l":
+		m.activeGroup = (m.activeGroup + 1) % m.totalTabs()
+		m.cursor = 0
+		m.inputBuf = ""
+		return m, m.onTabSwitch()
+	case "shift+tab", "left", "h":
+		m.activeGroup = (m.activeGroup - 1 + m.totalTabs()) % m.totalTabs()
+		m.cursor = 0
+		m.inputBuf = ""
+		return m, m.onTabSwitch()
+	}
+
+	return m.handleWorkspaceKey(s)
+}
+
+func (m *Model) onTabSwitch() tea.Cmd {
+	if m.IsHistoryTab() && !m.history.Loaded && !m.history.Scanning {
+		m.history.Scanning = true
+		return ScanSessionsCmd()
+	}
+	return nil
+}
+
+// --- Workspace Tab 按键 ---
+
+func (m *Model) handleWorkspaceKey(s string) (*Model, tea.Cmd) {
+	switch s {
 	case "up", "k":
 		m.moveCursor(-1)
 	case "down", "j":
@@ -77,13 +131,99 @@ func (m *Model) Update(msg tea.Msg) (tea.Model, tea.Cmd) {
 			m.inputBuf += s
 		}
 	}
-	case tea.WindowSizeMsg:
-		m.width = msg.Width
-		m.height = msg.Height
+	return m, nil
+}
+
+// --- HISTORY Tab 按键 ---
+
+func (m *Model) handleHistoryKey(s string) (*Model, tea.Cmd) {
+	switch s {
+	case "up", "k":
+		if m.history.FocusPanel == 0 {
+			m.moveHistoryDir(-1)
+		} else {
+			m.moveHistorySess(-1)
+		}
+	case "down", "j":
+		if m.history.FocusPanel == 0 {
+			m.moveHistoryDir(1)
+		} else {
+			m.moveHistorySess(1)
+		}
+	case "tab", "right", "l":
+		if m.history.FocusPanel < 1 {
+			m.history.FocusPanel = 1
+		}
+	case "shift+tab", "left", "h":
+		if m.history.FocusPanel > 0 {
+			m.history.FocusPanel = 0
+		}
+	case "enter":
+		if m.history.FocusPanel == 0 {
+			// 在左栏按 enter 切到中栏
+			m.history.FocusPanel = 1
+		} else {
+			return m.resumeSelected()
+		}
 	}
 	return m, nil
 }
 
+func (m *Model) moveHistoryDir(dir int) {
+	if len(m.history.Projects) == 0 {
+		return
+	}
+	m.history.DirCursor += dir
+	if m.history.DirCursor < 0 {
+		m.history.DirCursor = len(m.history.Projects) - 1
+	}
+	if m.history.DirCursor >= len(m.history.Projects) {
+		m.history.DirCursor = 0
+	}
+	m.history.SessCursor = 0
+}
+
+func (m *Model) moveHistorySess(dir int) {
+	sessions := m.currentSessions()
+	if len(sessions) == 0 {
+		return
+	}
+	m.history.SessCursor += dir
+	if m.history.SessCursor < 0 {
+		m.history.SessCursor = len(sessions) - 1
+	}
+	if m.history.SessCursor >= len(sessions) {
+		m.history.SessCursor = 0
+	}
+}
+
+func (m *Model) currentSessions() []*Session {
+	if m.history.DirCursor < len(m.history.Projects) {
+		return m.history.Projects[m.history.DirCursor].Sessions
+	}
+	return nil
+}
+
+func (m *Model) currentSession() *Session {
+	sessions := m.currentSessions()
+	if len(sessions) == 0 || m.history.SessCursor >= len(sessions) {
+		return nil
+	}
+	return sessions[m.history.SessCursor]
+}
+
+func (m *Model) resumeSelected() (*Model, tea.Cmd) {
+	s := m.currentSession()
+	if s == nil {
+		return m, nil
+	}
+	go resumeSession(s)
+	m.launched = "resume: " + s.CustomTitle
+	return m, nil
+}
+
+// --- Workspace 光标 ---
+
 func (m *Model) moveCursor(dir int) {
 	svcs := WorkspacesByGroup(Groups[m.activeGroup].Label)
 	if len(svcs) == 0 {
@@ -146,6 +286,7 @@ func (m *Model) launchByInput() (*Model, tea.Cmd) {
 	return m, nil
 }
 
+// --- View ---
 
 func (m *Model) View() tea.View {
 	v := tea.NewView(m.render())
@@ -162,13 +303,11 @@ func (m *Model) render() string {
 
 	var b strings.Builder
 
-	// layout widths
-	listW := max(42, min(65, m.width*55/100))
-	detailW := max(30, m.width-listW-3)
-
 	// ── header: title + tabs ──
 	b.WriteString(style.TitleStyle.Render(" u-tabs "))
 	sep := style.TabSep.Render(" | ")
+
+	// Workspace Tabs
 	for i, g := range Groups {
 		if i > 0 {
 			b.WriteString(sep)
@@ -187,19 +326,83 @@ func (m *Model) render() string {
 			b.WriteString(style.TabInactiveStyle.Render(label))
 		}
 	}
+
+	// HISTORY Tab
+	b.WriteString(sep)
+	histLabel := " HISTORY 历史 "
+	if m.IsHistoryTab() {
+		gs := style.GroupStyles["HISTORY"]
+		b.WriteString(lipgloss.NewStyle().
+			Bold(true).Background(style.BgPanel).Foreground(gs.GetForeground()).
+			Padding(0, 1).Render(histLabel))
+	} else {
+		b.WriteString(style.TabInactiveStyle.Render(histLabel))
+	}
+
 	b.WriteString("\n")
 	b.WriteString(lipgloss.NewStyle().Foreground(style.BgPanel).Render(strings.Repeat("─", m.width)))
 	b.WriteString("\n")
 
+	// ── 内容区 ──
+	if m.IsHistoryTab() {
+		b.WriteString(m.renderHistory())
+	} else {
+		b.WriteString(m.renderWorkspace())
+	}
+
+	// ── footer ──
+	b.WriteString("\n")
+	if m.inputBuf != "" {
+		b.WriteString(style.InputStyle.Render(fmt.Sprintf(" ▶ num:%s [Enter]go [Esc]cancel", m.inputBuf)))
+	}
+	if m.launched != "" {
+		b.WriteString(lipgloss.NewStyle().Foreground(style.Accent).Render(fmt.Sprintf(" ✓ %s", m.launched)))
+		m.launched = ""
+	}
+	b.WriteString("\n")
+
+	helpParts := m.renderHelp()
+	b.WriteString(" " + strings.Join(helpParts, "  "))
+
+	if hint := ConfigHint(); hint != "" {
+		b.WriteString("\n" + hint)
+	}
+	return b.String()
+}
+
+func (m *Model) renderHelp() []string {
+	if m.IsHistoryTab() {
+		return []string{
+			m.fmtHelp("j/k", "sel"),
+			m.fmtHelp("Tab", "→panel"),
+			m.fmtHelp("Enter", "resume"),
+			m.fmtHelp("1-"+fmt.Sprintf("%d", m.totalTabs()), "tab"),
+			m.fmtHelp("q", "quit"),
+		}
+	}
+	return []string{
+		m.fmtHelp("j/k", "sel"),
+		m.fmtHelp("Enter", "run"),
+		m.fmtHelp("Space", "multi"),
+		m.fmtHelp("Tab", "group"),
+		m.fmtHelp("q", "quit"),
+	}
+}
+
+// --- Workspace 渲染 ---
+
+func (m *Model) renderWorkspace() string {
+	listW := max(42, min(65, m.width*55/100))
+	detailW := max(30, m.width-listW-3)
+
 	g := Groups[m.activeGroup]
 	gs, _ := style.GroupStyles[g.Label]
 	svcs := WorkspacesByGroup(g.Label)
 	if len(svcs) == 0 {
-		b.WriteString(style.SubtitleStyle.Render("  empty"))
-		return b.String()
+		return style.SubtitleStyle.Render("  empty")
 	}
 
-	// ═══ left: list ═══
+	// 左栏: 列表
 	var left strings.Builder
 	innerW := listW - 4
 	for i, ws := range svcs {
@@ -209,19 +412,26 @@ func (m *Model) render() string {
 		}
 		mark := " "
 		if m.selected[ws.Index] {
-			mark = style.MarkStyle.Render("✓")
+			mark = "✓"
+		}
+
+		if i == m.cursor {
+			// 选中行：纯文本，让 SelStyle 统一着色
+			prefix := cur + " " + mark + " " + fmt.Sprintf("%02d", ws.N) + " "
+			remainW := max(10, innerW-len(prefix))
+			text := truncateByWidth(ws.Title+"  "+ws.Prompt, remainW)
+			left.WriteString(style.SelStyle.Width(innerW).Render(prefix + text))
+		} else {
+			// 非选中行：子样式着色
+			markStr := " "
+			if m.selected[ws.Index] {
+				markStr = style.MarkStyle.Render("✓")
 			}
 			num := style.NumStyle.Render(fmt.Sprintf("%02d", ws.N))
-
-		prefix := cur + " " + mark + " " + num + " "
+			prefix := cur + " " + markStr + " " + num + " "
 			remainW := max(10, innerW-lipgloss.Width(prefix))
 			text := truncateByWidth(ws.Title+"  "+ws.Prompt, remainW)
-
-		line := prefix + text
-		if i == m.cursor {
-			left.WriteString(style.SelStyle.Width(innerW).Render(line))
-		} else {
-			left.WriteString(style.NormStyle.Render(line))
+			left.WriteString(style.NormStyle.Render(prefix + text))
 		}
 		left.WriteString("\n")
 	}
@@ -234,7 +444,7 @@ func (m *Model) render() string {
 		Padding(0, 1).
 		Render(groupHeader + "\n" + left.String())
 
-	// ═══ right: detail ═══
+	// 右栏: 详情
 	var right strings.Builder
 	if m.cursor < len(svcs) {
 		ws := svcs[m.cursor]
@@ -279,34 +489,165 @@ func (m *Model) render() string {
 		Padding(0, 1).
 		Render(right.String())
 
-	b.WriteString(lipgloss.JoinHorizontal(lipgloss.Left, listBox, " ", detailBox))
-
-	// ── footer ──
-	b.WriteString("\n")
-	if m.inputBuf != "" {
-		b.WriteString(style.InputStyle.Render(fmt.Sprintf(" ▶ num:%s [Enter]go [Esc]cancel", m.inputBuf)))
-	}
-	if m.launched != "" {
-		b.WriteString(lipgloss.NewStyle().Foreground(style.Accent).Render(fmt.Sprintf(" ✓ %s", m.launched)))
-		m.launched = ""
-	}
-	b.WriteString("\n")
-
-	helpParts := []string{
-		m.fmtHelp("j/k", "sel"),
-		m.fmtHelp("Enter", "run"),
-		m.fmtHelp("Space", "multi"),
-		m.fmtHelp("Tab", "group"),
-		m.fmtHelp("q", "quit"),
-	}
-	b.WriteString(" " + strings.Join(helpParts, "  "))
-
-	if hint := ConfigHint(); hint != "" {
-		b.WriteString("\n" + hint)
-	}
-	return b.String()
+	return lipgloss.JoinHorizontal(lipgloss.Left, listBox, " ", detailBox)
 }
 
+// --- HISTORY 三栏渲染 ---
+
+func (m *Model) renderHistory() string {
+	if m.history.Scanning {
+		return style.ScanningStyle.Render("  scanning sessions...")
+	}
+	if !m.history.Loaded {
+		return style.ScanningStyle.Render("  press Tab to load sessions...")
+	}
+	if len(m.history.Projects) == 0 {
+		return style.SubtitleStyle.Render("  no sessions found")
+	}
+
+	// 三栏宽度分配
+	avail := m.width - 4 // borders + gaps
+	dirW := max(20, avail*20/100)
+	sessW := max(30, avail*40/100)
+	detailW := max(20, avail-dirW-sessW)
+
+	// 左栏: 目录列表
+	dirBox := m.renderDirPanel(dirW)
+	// 中栏: 会话列表
+	sessBox := m.renderSessPanel(sessW)
+	// 右栏: 详情
+	detailBox := m.renderHistoryDetail(detailW)
+
+	return lipgloss.JoinHorizontal(lipgloss.Left, dirBox, " ", sessBox, " ", detailBox)
+}
+
+func (m *Model) renderDirPanel(w int) string {
+	var b strings.Builder
+	innerW := w - 4
+
+	b.WriteString(style.DetailTitle.Render(" dirs "))
+	b.WriteString("\n")
+
+	for i, pd := range m.history.Projects {
+		cur := " "
+		if i == m.history.DirCursor {
+			cur = "▸"
+		}
+		name := truncateByWidth(pd.DirShort, max(8, innerW-8))
+
+		if i == m.history.DirCursor && m.history.FocusPanel == 0 {
+			line := fmt.Sprintf("%s %s (%d)", cur, name, len(pd.Sessions))
+			b.WriteString(style.SelStyle.Width(innerW).Render(line))
+		} else {
+			cnt := style.DirCountStyle.Render(fmt.Sprintf("(%d)", len(pd.Sessions)))
+			line := fmt.Sprintf("%s %s %s", cur, name, cnt)
+			b.WriteString(style.NormStyle.Render(line))
+		}
+		b.WriteString("\n")
+	}
+
+	return lipgloss.NewStyle().
+		Border(lipgloss.NormalBorder()).
+		BorderForeground(style.BgPanel).
+		Width(w).
+		Padding(0, 1).
+		Render(b.String())
+}
+
+func (m *Model) renderSessPanel(w int) string {
+	var b strings.Builder
+	innerW := w - 4
+
+	b.WriteString(style.DetailTitle.Render(" sessions "))
+	b.WriteString("\n")
+
+	sessions := m.currentSessions()
+	if len(sessions) == 0 {
+		b.WriteString(style.SubtitleStyle.Render("  no sessions"))
+	} else {
+		for i, s := range sessions {
+			cur := " "
+			if i == m.history.SessCursor {
+				cur = "▸"
+			}
+			timeStr := s.StartTime.Format("01-02 15:04")
+			title := s.DisplayTitle()
+			remainW := max(10, innerW-10)
+			text := truncateByWidth(title, remainW)
+
+			if i == m.history.SessCursor && m.history.FocusPanel == 1 {
+				line := fmt.Sprintf("%s %s %s", cur, timeStr, text)
+				b.WriteString(style.SelStyle.Width(innerW).Render(line))
+			} else {
+				line := fmt.Sprintf("%s %s %s", cur, style.SessionTimeStyle.Render(timeStr), text)
+				b.WriteString(style.NormStyle.Render(line))
+			}
+
+			b.WriteString("\n")
+		}
+	}
+
+	return lipgloss.NewStyle().
+		Border(lipgloss.NormalBorder()).
+		BorderForeground(style.BgPanel).
+		Width(w).
+		Padding(0, 1).
+		Render(b.String())
+}
+
+func (m *Model) renderHistoryDetail(w int) string {
+	var b strings.Builder
+
+	s := m.currentSession()
+	if s == nil {
+		b.WriteString(lipgloss.NewStyle().Foreground(style.Dim).Render(" ← select to view"))
+	} else {
+		b.WriteString(style.DetailTitle.Render(" detail "))
+		b.WriteString(lipgloss.NewStyle().Foreground(style.BgPanel).Render(strings.Repeat("─", w-12)))
+		b.WriteString("\n\n")
+
+		rows := []struct {
+			key string
+			val string
+			sty lipgloss.Style
+		}{
+			{"title", s.CustomTitle, style.ValStyle},
+			{"dir", s.Cwd, style.ValStyle},
+			{"time", fmt.Sprintf("%s ~ %s", s.StartTime.Format("01-02 15:04"), s.EndTime.Format("15:04")), style.NumStyle},
+			{"msgs", fmt.Sprintf("%d", s.MsgCount), style.SessionMsgCntStyle},
+		}
+		for _, r := range rows {
+			b.WriteString("  ")
+			b.WriteString(style.KeyStyle.Render(r.key))
+			b.WriteString("  ")
+			b.WriteString(r.sty.Render(r.val))
+			b.WriteString("\n")
+		}
+
+		// 摘要
+		summary := s.DisplaySummary()
+		if summary != "" {
+			b.WriteString("\n")
+			b.WriteString(lipgloss.NewStyle().Foreground(style.BgPanel).Render("  " + strings.Repeat("─", w-6)))
+			b.WriteString("\n")
+			b.WriteString(style.SessionSummaryStyle.Render("  " + truncateByWidth(summary, w-6)))
+			b.WriteString("\n")
+		}
+
+		b.WriteString("\n")
+		b.WriteString(lipgloss.NewStyle().Foreground(style.Dim).Render("  [Enter]resume"))
+	}
+
+	return lipgloss.NewStyle().
+		Border(lipgloss.NormalBorder()).
+		BorderForeground(style.BgPanel).
+		Width(w).
+		Padding(0, 1).
+		Render(b.String())
+}
+
+// --- 工具 ---
+
 func (m *Model) fmtHelp(key, desc string) string {
 	return lipgloss.NewStyle().Foreground(style.Accent).Render(key) +
 		lipgloss.NewStyle().Foreground(style.Dim).Render(":" + desc)
@@ -346,22 +687,39 @@ func runeWidth(r rune) int {
 	return 1
 }
 
-// --- launch ---
+// --- 启动 ---
 
-func launchWorkspace(ws Workspace) {
-	script := buildLaunchScript(ws)
+func launchInWt(dir, script string) {
 	encoded := encodePSCommand(script)
 	color := fmt.Sprintf("#%02X%02X%02X", randRange(80, 255), randRange(80, 255), randRange(80, 255))
 	cmd := exec.Command("wt.exe", "-w", "0",
-		"-d", ws.Dir,
+		"-d", dir,
 		"--tabColor", color,
 		"pwsh", "-NoExit", "-EncodedCommand", encoded,
 	)
 	if err := cmd.Start(); err != nil {
-		log.Printf("[u-tabs] launch fail %s(%d): %v", ws.Title, ws.N, err)
+		log.Printf("[u-tabs] launch fail: %v", err)
 	}
 }
 
+func launchWorkspace(ws Workspace) {
+	script := buildLaunchScript(ws)
+	launchInWt(ws.Dir, script)
+}
+
+func resumeSession(s *Session) {
+	cwd := strings.ReplaceAll(s.Cwd, "/", "\\")
+	title := s.CustomTitle
+	if title == "" {
+		title = s.ID[:8]
+	}
+	script := fmt.Sprintf(`$Host.UI.RawUI.WindowTitle = "resume: %s"
+Write-Host "=== Resuming: %s ===" -ForegroundColor Cyan
+cd "%s"
+claude -r %s`, title, title, cwd, s.ID)
+	launchInWt(cwd, script)
+}
+
 func buildLaunchScript(ws Workspace) string {
 	return fmt.Sprintf(`$Host.UI.RawUI.WindowTitle = "%s"
 Write-Host "=== %s ===" -ForegroundColor Cyan

internal/history.go

@@ -0,0 +1,406 @@
+package internal
+
+import (
+	"bufio"
+	"bytes"
+	"encoding/json"
+	"log"
+	"os"
+	"path/filepath"
+	"sort"
+	"strings"
+	"time"
+
+	"charm.land/bubbletea/v2"
+)
+
+// Session 单个会话的元数据
+type Session struct {
+	ID          string    // UUID (文件名)
+	CustomTitle string    // customTitle 字段
+	Cwd         string    // 实际工作目录
+	StartTime   time.Time // 首条 timestamp
+	EndTime     time.Time // 末条 timestamp
+	MsgCount    int       // user + assistant 消息数
+	FirstMsg    string    // 首条用户消息 (截断)
+	AwaySummary string    // away_summary 系统摘要
+	AISummary   string    // AI 生成的摘要 (缓存)
+}
+
+// ProjectDir 按目录分组的会话集合
+type ProjectDir struct {
+	Dir      string     // 完整路径
+	DirShort string     // 显示名 (路径最后一段)
+	Sessions []*Session // 按时间倒序
+}
+
+// DisplayTitle 返回会话显示标题
+func (s *Session) DisplayTitle() string {
+	if s.AISummary != "" {
+		return s.AISummary
+	}
+	if s.FirstMsg != "" {
+		return s.FirstMsg
+	}
+	if s.CustomTitle != "" {
+		return s.CustomTitle
+	}
+	return s.ID[:8]
+}
+
+// DisplaySummary 返回会话摘要
+func (s *Session) DisplaySummary() string {
+	if s.AwaySummary != "" {
+		return s.AwaySummary
+	}
+	return s.FirstMsg
+}
+
+// HistoryState HISTORY Tab 视图状态
+type HistoryState struct {
+	Projects   []*ProjectDir
+	DirCursor  int // 左栏光标
+	SessCursor int // 中栏光标
+	FocusPanel int // 0=左栏 1=中栏
+	Loaded     bool
+	Scanning   bool
+}
+
+// IsHistoryTab 判断当前是否在 HISTORY Tab
+func (m *Model) IsHistoryTab() bool {
+	return m.activeGroup == len(Groups)
+}
+
+// --- 扫描 ---
+
+type ScanCompleteMsg struct {
+	Projects []*ProjectDir
+}
+
+func ScanSessionsCmd() tea.Cmd {
+	return func() tea.Msg {
+		return ScanCompleteMsg{Projects: scanAllProjects()}
+	}
+}
+
+func scanAllProjects() []*ProjectDir {
+	home, err := os.UserHomeDir()
+	if err != nil {
+		return nil
+	}
+	projectsDir := filepath.Join(home, ".claude", "projects")
+	entries, err := os.ReadDir(projectsDir)
+	if err != nil {
+		return nil
+	}
+
+	cache := loadCache(home)
+	dirMap := make(map[string]*ProjectDir)
+
+	for _, entry := range entries {
+		if !entry.IsDir() {
+			continue
+		}
+		projectPath := filepath.Join(projectsDir, entry.Name())
+		files, err := os.ReadDir(projectPath)
+		if err != nil {
+			continue
+		}
+		for _, f := range files {
+			if f.IsDir() || !strings.HasSuffix(f.Name(), ".jsonl") {
+				continue
+			}
+			sessionID := strings.TrimSuffix(f.Name(), ".jsonl")
+			filePath := filepath.Join(projectPath, f.Name())
+			info, err := f.Info()
+			if err != nil {
+				continue
+			}
+
+			if cached, ok := cache[sessionID]; ok && cached.ModTime.Equal(info.ModTime()) {
+				addSessionToDir(dirMap, cached.ToSession(sessionID))
+				continue
+			}
+
+			session := scanSessionFile(filePath, sessionID)
+			if session == nil || session.Cwd == "" {
+				continue
+			}
+			addSessionToDir(dirMap, session)
+			cache[sessionID] = cacheEntryFrom(session, info.ModTime())
+		}
+	}
+
+	saveCache(home, cache)
+
+	result := make([]*ProjectDir, 0, len(dirMap))
+	for _, pd := range dirMap {
+		sort.Slice(pd.Sessions, func(i, j int) bool {
+			return pd.Sessions[i].StartTime.After(pd.Sessions[j].StartTime)
+		})
+		result = append(result, pd)
+	}
+	sort.Slice(result, func(i, j int) bool {
+		return result[i].Dir < result[j].Dir
+	})
+	return result
+}
+
+func addSessionToDir(dirMap map[string]*ProjectDir, s *Session) {
+	cwd := strings.ReplaceAll(s.Cwd, "\\", "/")
+	pd, ok := dirMap[cwd]
+	if !ok {
+		pd = &ProjectDir{Dir: cwd, DirShort: filepath.Base(cwd)}
+		dirMap[cwd] = pd
+	}
+	pd.Sessions = append(pd.Sessions, s)
+}
+
+// --- JSONL 扫描 ---
+
+const scanLineLimit = 500
+
+func scanSessionFile(path string, sessionID string) *Session {
+	f, err := os.Open(path)
+	if err != nil {
+		return nil
+	}
+	defer f.Close()
+
+	s := &Session{ID: sessionID}
+	scanner := bufio.NewScanner(f)
+	scanner.Buffer(make([]byte, 0, 64*1024), 1024*1024)
+
+	lineCount := 0
+	firstMsgFound := false
+	scannedLines := 0 // 有效行（含 type 的）
+
+	for scanner.Scan() {
+		lineCount++
+		line := scanner.Bytes()
+
+		if !hasType(line) {
+			continue
+		}
+		scannedLines++
+
+		// cwd — 统一为正斜杠
+		if s.Cwd == "" {
+			extractField(line, `"cwd":"`, &s.Cwd)
+			s.Cwd = strings.ReplaceAll(s.Cwd, "\\", "/")
+		}
+
+		// timestamp
+		var ts string
+		if extractField(line, `"timestamp":"`, &ts) {
+			if t, err := time.Parse(time.RFC3339Nano, ts); err == nil {
+				if s.StartTime.IsZero() || t.Before(s.StartTime) {
+					s.StartTime = t
+				}
+				if t.After(s.EndTime) {
+					s.EndTime = t
+				}
+			}
+		}
+
+		switch {
+		case matchType(line, "custom-title"):
+			extractField(line, `"customTitle":"`, &s.CustomTitle)
+		case matchSubtype(line, "away_summary"):
+			extractField(line, `"content":"`, &s.AwaySummary)
+		case matchType(line, "user"):
+			if bytes.Contains(line, []byte(`"tool_use_id"`)) || bytes.Contains(line, []byte(`"isMeta":true`)) {
+				continue
+			}
+			s.MsgCount++
+			if !firstMsgFound {
+				if msg := extractUserMsg(line); msg != "" {
+					s.FirstMsg = truncStr(msg, 80)
+					firstMsgFound = true
+				}
+			}
+		case matchType(line, "assistant"):
+			s.MsgCount++
+		}
+
+		if lineCount > scanLineLimit {
+			break
+		}
+	}
+
+	// 按 scannedLines/lineCount 比例估算总消息数
+	if lineCount > scanLineLimit && scannedLines > 0 {
+		ratio := float64(lineCount) / float64(scanLineLimit)
+		s.MsgCount = int(float64(s.MsgCount) * ratio)
+	}
+
+	return s
+}
+
+// matchType 检查 JSON 行是否包含指定 type 值
+func matchType(line []byte, typeName string) bool {
+	compact := `"type":"` + typeName + `"`
+	spaced := `"type": "` + typeName + `"`
+	return bytes.Contains(line, []byte(compact)) || bytes.Contains(line, []byte(spaced))
+}
+
+// matchSubtype 检查 JSON 行是否包含指定 subtype 值
+func matchSubtype(line []byte, subName string) bool {
+	compact := `"subtype":"` + subName + `"`
+	spaced := `"subtype": "` + subName + `"`
+	return bytes.Contains(line, []byte(compact)) || bytes.Contains(line, []byte(spaced))
+}
+
+// hasType 快速过滤：行是否包含 type 字段
+func hasType(line []byte) bool {
+	return bytes.Contains(line, []byte(`"type":"`)) || bytes.Contains(line, []byte(`"type": "`))
+}
+
+// extractField 从 JSON 行中提取 "key":"value" 的值
+func extractField(line []byte, prefix string, out *string) bool {
+	idx := bytes.Index(line, []byte(prefix))
+	if idx < 0 {
+		return false
+	}
+	// prefix 长度 = len("key\":")，data 从引号开始
+	return extractJSONString(line[idx+len(prefix)-1:], out)
+}
+
+func extractUserMsg(line []byte) string {
+	// string 格式: "content":"xxx"
+	if idx := bytes.Index(line, []byte(`"content":"`)); idx >= 0 {
+		var content string
+		extractJSONString(line[idx+10:], &content)
+		if content != "" && !strings.HasPrefix(content, "<command") &&
+			!strings.HasPrefix(content, "<system-reminder") &&
+			!strings.HasPrefix(content, "[Request interrupted") {
+			return content
+		}
+	}
+
+	// array 格式: [{"type":"text","text":"xxx"}]
+	if idx := bytes.Index(line, []byte(`"type":"text"`)); idx >= 0 {
+		searchStart := max(0, idx-200)
+		region := line[searchStart:]
+		if tidx := bytes.Index(region, []byte(`"text":"`)); tidx >= 0 {
+			var text string
+			if extractJSONString(region[tidx+6:], &text) && text != "" &&
+				!strings.HasPrefix(text, "Base directory") {
+				return text
+			}
+		}
+	}
+	return ""
+}
+
+// extractJSONString 从 " 开头的 JSON 数据中提取字符串值
+func extractJSONString(data []byte, out *string) bool {
+	if len(data) == 0 || data[0] != '"' {
+		return false
+	}
+	// 找结束引号（处理转义）
+	var s string
+	if json.Unmarshal(data[:findStringEnd(data)], &s) == nil {
+		*out = s
+		return true
+	}
+	return false
+}
+
+// findStringEnd 从 " 开始找到结束引号的位置（含）
+func findStringEnd(data []byte) int {
+	escaped := false
+	for i := 1; i < len(data); i++ {
+		if escaped {
+			escaped = false
+			continue
+		}
+		if data[i] == '\\' {
+			escaped = true
+			continue
+		}
+		if data[i] == '"' {
+			return i + 1
+		}
+	}
+	return len(data)
+}
+
+// --- 缓存 ---
+
+const cacheVersion = 1
+
+type cacheFile struct {
+	Version  int                      `json:"version"`
+	Sessions map[string]*cacheEntry   `json:"sessions"`
+}
+
+type cacheEntry struct {
+	ModTime     time.Time `json:"modTime"`
+	CustomTitle string    `json:"customTitle"`
+	Cwd         string    `json:"cwd"`
+	StartTime   time.Time `json:"startTime"`
+	EndTime     time.Time `json:"endTime"`
+	MsgCount    int       `json:"msgCount"`
+	FirstMsg    string    `json:"firstMsg"`
+	AwaySummary string    `json:"awaySummary"`
+	AISummary   string    `json:"aiSummary"`
+}
+
+func (e *cacheEntry) ToSession(id string) *Session {
+	return &Session{
+		ID: id, CustomTitle: e.CustomTitle, Cwd: e.Cwd,
+		StartTime: e.StartTime, EndTime: e.EndTime,
+		MsgCount: e.MsgCount, FirstMsg: e.FirstMsg,
+		AwaySummary: e.AwaySummary, AISummary: e.AISummary,
+	}
+}
+
+func cacheEntryFrom(s *Session, modTime time.Time) *cacheEntry {
+	return &cacheEntry{
+		ModTime: modTime, CustomTitle: s.CustomTitle, Cwd: s.Cwd,
+		StartTime: s.StartTime, EndTime: s.EndTime,
+		MsgCount: s.MsgCount, FirstMsg: s.FirstMsg,
+		AwaySummary: s.AwaySummary, AISummary: s.AISummary,
+	}
+}
+
+func cachePath(home string) string {
+	return filepath.Join(home, ".u-tabs", "session-cache.json")
+}
+
+func loadCache(home string) map[string]*cacheEntry {
+	data, err := os.ReadFile(cachePath(home))
+	if err != nil {
+		return make(map[string]*cacheEntry)
+	}
+	var cf cacheFile
+	if json.Unmarshal(data, &cf) != nil || cf.Version != cacheVersion {
+		return make(map[string]*cacheEntry)
+	}
+	return cf.Sessions
+}
+
+func saveCache(home string, m map[string]*cacheEntry) {
+	cf := cacheFile{Version: cacheVersion, Sessions: m}
+	data, err := json.Marshal(cf)
+	if err != nil {
+		return
+	}
+	dir := filepath.Join(home, ".u-tabs")
+	if err := os.MkdirAll(dir, 0o755); err != nil {
+		log.Printf("[u-tabs] cache mkdir fail: %v", err)
+		return
+	}
+	if err := os.WriteFile(cachePath(home), data, 0o644); err != nil {
+		log.Printf("[u-tabs] cache write fail: %v", err)
+	}
+}
+
+func truncStr(s string, maxRunes int) string {
+	runes := []rune(s)
+	if len(runes) <= maxRunes {
+		return s
+	}
+	return string(runes[:maxRunes]) + "..."
+}

internal/style/style.go

@@ -47,4 +47,14 @@ var GroupStyles = map[string]lipgloss.Style{
 	"TOOLS":   lipgloss.NewStyle().Bold(true).Foreground(Warning),
 	"ME":      lipgloss.NewStyle().Bold(true).Foreground(Purple),
 	"TEMP":    lipgloss.NewStyle().Bold(true).Foreground(Cyan),
+	"HISTORY": lipgloss.NewStyle().Bold(true).Foreground(Cyan),
 }
+
+// --- 历史会话专用样式 ---
+var (
+	SessionTimeStyle    = lipgloss.NewStyle().Foreground(Dim).Width(12).Inline(true)
+	SessionMsgCntStyle  = lipgloss.NewStyle().Foreground(Accent).Inline(true)
+	SessionSummaryStyle = lipgloss.NewStyle().Foreground(Dim).Italic(true).Inline(true)
+	DirCountStyle       = lipgloss.NewStyle().Foreground(Accent).Inline(true)
+	ScanningStyle       = lipgloss.NewStyle().Foreground(Warning).Bold(true)
+)