refactor(tui): extract shared table rendering, fix cursor bounds

- New table_helpers.go with renderTable() and shared styles
- Remove 4 duplicated style blocks (header/cell/selected/border)
  from tab_alerts.go and tab_users.go
- All 3 tab views now use renderTable() for offset/end calc,
  selected row highlighting, and table construction
- Sites tab keeps siteGroupStyle via StyleOverride callback
- Clamp cursor to list length at end of refreshData() to prevent
  index-out-of-bounds after concurrent list changes
- Fix off-by-one in tab click handler (i <= maxTabs → i < tabCount)

internal/tui/tab_alerts.go

@@ -7,25 +7,6 @@ import (
 	tea "github.com/charmbracelet/bubbletea"
 	"github.com/charmbracelet/huh"
 	"github.com/charmbracelet/lipgloss"
-	"github.com/charmbracelet/lipgloss/table"
-)
-
-var (
-	alertHeaderStyle = lipgloss.NewStyle().
-				Foreground(lipgloss.Color("#7D56F4")).
-				Bold(true).
-				Padding(0, 1)
-
-	alertCellStyle = lipgloss.NewStyle().Padding(0, 1)
-
-	alertSelectedStyle = lipgloss.NewStyle().
-				Padding(0, 1).
-				Bold(true).
-				Foreground(lipgloss.Color("#ffffff")).
-				Background(lipgloss.Color("#3b3b5c"))
-
-	alertBorderStyle = lipgloss.NewStyle().
-				Foreground(lipgloss.Color("#444"))
 )
 
 type alertFormData struct {
@@ -97,49 +78,27 @@ func (m Model) viewAlertsTab() string {
 		return "\n  No alert channels configured. Press [n] to add one."
 	}
 
-	end := m.tableOffset + m.maxTableRows
+	return m.renderTable(
-	if end > len(m.alerts) {
+		[]string{"#", "NAME", "TYPE", "CONFIG"},
-		end = len(m.alerts)
+		len(m.alerts),
-	}
+		func(start, end int) [][]string {
-
+			var rows [][]string
-	selectedVisual := m.cursor - m.tableOffset
+			for i := start; i < end; i++ {
-
+				a := m.alerts[i]
-	var rows [][]string
+				rows = append(rows, []string{
-	for i := m.tableOffset; i < end; i++ {
+					fmt.Sprintf("%d", i+1),
-		alert := m.alerts[i]
+					m.zones.Mark(fmt.Sprintf("alert-%d", i), limitStr(a.Name, 15)),
-		rows = append(rows, []string{
+					fmtAlertType(a.Type),
-			fmt.Sprintf("%d", i+1),
+					fmtAlertConfig(struct {
-			m.zones.Mark(fmt.Sprintf("alert-%d", i), limitStr(alert.Name, 15)),
+						Type     string
-			fmtAlertType(alert.Type),
+						Settings map[string]string
-			fmtAlertConfig(struct {
+					}{a.Type, a.Settings}),
-				Type     string
+				})
-				Settings map[string]string
-			}{alert.Type, alert.Settings}),
-		})
-	}
-
-	tableWidth := m.termWidth - 6
-	if tableWidth < 40 {
-		tableWidth = 40
-	}
-
-	t := table.New().
-		Border(lipgloss.RoundedBorder()).
-		BorderStyle(alertBorderStyle).
-		Width(tableWidth).
-		Headers("#", "NAME", "TYPE", "CONFIG").
-		Rows(rows...).
-		StyleFunc(func(row, col int) lipgloss.Style {
-			if row == table.HeaderRow {
-				return alertHeaderStyle
 			}
-			if row == selectedVisual {
+			return rows
-				return alertSelectedStyle
+		},
-			}
+		nil, nil,
-			return alertCellStyle
+	)
-		})
-
-	return "\n" + t.Render()
 }
 
 func (m *Model) initAlertHuhForm() tea.Cmd {

internal/tui/tab_sites.go

@@ -12,33 +12,14 @@ import (
 	tea "github.com/charmbracelet/bubbletea"
 	"github.com/charmbracelet/huh"
 	"github.com/charmbracelet/lipgloss"
-	"github.com/charmbracelet/lipgloss/table"
 )
 
 var sparkChars = []rune{'▁', '▂', '▃', '▄', '▅', '▆', '▇', '█'}
 
-var (
+var siteGroupStyle = lipgloss.NewStyle().
-	siteHeaderStyle = lipgloss.NewStyle().
+	Padding(0, 1).
-			Foreground(lipgloss.Color("#7D56F4")).
+	Bold(true).
-			Bold(true).
+	Foreground(lipgloss.Color("#7D56F4"))
-			Padding(0, 1)
-
-	siteCellStyle = lipgloss.NewStyle().Padding(0, 1)
-
-	siteSelectedStyle = lipgloss.NewStyle().
-				Padding(0, 1).
-				Bold(true).
-				Foreground(lipgloss.Color("#ffffff")).
-				Background(lipgloss.Color("#3b3b5c"))
-
-	siteBorderStyle = lipgloss.NewStyle().
-			Foreground(lipgloss.Color("#444"))
-
-	siteGroupStyle = lipgloss.NewStyle().
-			Padding(0, 1).
-			Bold(true).
-			Foreground(lipgloss.Color("#7D56F4"))
-)
 
 type siteFormData struct {
 	Name        string
@@ -219,111 +200,80 @@ func (m Model) viewSitesTab() string {
 		return "\n  No sites configured. Press [n] to add one."
 	}
 
-	end := m.tableOffset + m.maxTableRows
-	if end > len(m.sites) {
-		end = len(m.sites)
-	}
-
-	selectedVisual := m.cursor - m.tableOffset
-
-	var rows [][]string
-	var groupRows []int
-	for i := m.tableOffset; i < end; i++ {
-		site := m.sites[i]
-
-		if site.Type == "group" {
-			groupRows = append(groupRows, i-m.tableOffset)
-			arrow := "▾"
-			if m.collapsed[site.ID] {
-				arrow = "▸"
-			}
-			rows = append(rows, []string{
-				strconv.Itoa(i + 1),
-				m.zones.Mark(fmt.Sprintf("site-%d", i), arrow+" "+limitStr(site.Name, 11)),
-				"group",
-				fmtStatus(site.Status, site.Paused),
-				subtleStyle.Render("—"),
-				subtleStyle.Render("—"),
-				subtleStyle.Render(strings.Repeat("·", sparkWidth)),
-				subtleStyle.Render("-"),
-				subtleStyle.Render("—"),
-			})
-			continue
-		}
-
-		name := site.Name
-		if site.ParentID > 0 {
-			prefix := "├"
-			if i+1 >= len(m.sites) || m.sites[i+1].ParentID != site.ParentID {
-				prefix = "└"
-			}
-			name = prefix + " " + limitStr(name, 11)
-		} else {
-			name = limitStr(name, 13)
-		}
-
-		hist, _ := monitor.GetHistory(site.ID)
-		var spark string
-		if site.Type == "push" {
-			spark = heartbeatSparkline(hist.Statuses, sparkWidth)
-		} else {
-			spark = latencySparkline(hist.Latencies, sparkWidth)
-		}
-
-		rows = append(rows, []string{
-			strconv.Itoa(i + 1),
-			m.zones.Mark(fmt.Sprintf("site-%d", i), name),
-			site.Type,
-			fmtStatus(site.Status, site.Paused),
-			fmtLatency(site.Latency),
-			fmtUptime(hist.TotalChecks, hist.UpChecks),
-			spark,
-			fmtSSL(site),
-			fmtRetries(site),
-		})
-	}
-
-	isGroupRow := func(row int) bool {
-		for _, g := range groupRows {
-			if g == row {
-				return true
-			}
-		}
-		return false
-	}
-
-	tableWidth := m.termWidth - 6
-	if tableWidth < 40 {
-		tableWidth = 40
-	}
-
-	// column widths: #=6, name=flex, type=10, status=10, latency=8, uptime=8, history=sparkWidth+4, ssl=7, retry=9
 	colWidths := []int{6, 0, 10, 10, 8, 8, sparkWidth + 4, 7, 9}
 
-	t := table.New().
+	var groupRows map[int]bool
-		Border(lipgloss.RoundedBorder()).
+	return m.renderTable(
-		BorderStyle(siteBorderStyle).
+		[]string{"#", "NAME", "TYPE", "STATUS", "LATENCY", "UPTIME", "HISTORY", "SSL", "RETRY"},
-		Width(tableWidth).
+		len(m.sites),
-		Headers("#", "NAME", "TYPE", "STATUS", "LATENCY", "UPTIME", "HISTORY", "SSL", "RETRY").
+		func(start, end int) [][]string {
-		Rows(rows...).
+			groupRows = make(map[int]bool)
-		StyleFunc(func(row, col int) lipgloss.Style {
+			var rows [][]string
-			var base lipgloss.Style
+			for i := start; i < end; i++ {
-			if row == table.HeaderRow {
+				site := m.sites[i]
-				base = siteHeaderStyle
-			} else if row == selectedVisual {
-				base = siteSelectedStyle
-			} else if isGroupRow(row) {
-				base = siteGroupStyle
-			} else {
-				base = siteCellStyle
-			}
-			if col < len(colWidths) && colWidths[col] > 0 {
-				base = base.Width(colWidths[col])
-			}
-			return base
-		})
 
-	return "\n" + t.Render()
+				if site.Type == "group" {
+					groupRows[i-start] = true
+					arrow := "▾"
+					if m.collapsed[site.ID] {
+						arrow = "▸"
+					}
+					rows = append(rows, []string{
+						strconv.Itoa(i + 1),
+						m.zones.Mark(fmt.Sprintf("site-%d", i), arrow+" "+limitStr(site.Name, 11)),
+						"group",
+						fmtStatus(site.Status, site.Paused),
+						subtleStyle.Render("—"),
+						subtleStyle.Render("—"),
+						subtleStyle.Render(strings.Repeat("·", sparkWidth)),
+						subtleStyle.Render("-"),
+						subtleStyle.Render("—"),
+					})
+					continue
+				}
+
+				name := site.Name
+				if site.ParentID > 0 {
+					prefix := "├"
+					if i+1 >= len(m.sites) || m.sites[i+1].ParentID != site.ParentID {
+						prefix = "└"
+					}
+					name = prefix + " " + limitStr(name, 11)
+				} else {
+					name = limitStr(name, 13)
+				}
+
+				hist, _ := monitor.GetHistory(site.ID)
+				var spark string
+				if site.Type == "push" {
+					spark = heartbeatSparkline(hist.Statuses, sparkWidth)
+				} else {
+					spark = latencySparkline(hist.Latencies, sparkWidth)
+				}
+
+				rows = append(rows, []string{
+					strconv.Itoa(i + 1),
+					m.zones.Mark(fmt.Sprintf("site-%d", i), name),
+					site.Type,
+					fmtStatus(site.Status, site.Paused),
+					fmtLatency(site.Latency),
+					fmtUptime(hist.TotalChecks, hist.UpChecks),
+					spark,
+					fmtSSL(site),
+					fmtRetries(site),
+				})
+			}
+			return rows
+		},
+		colWidths,
+		func(row, col int) *lipgloss.Style {
+			if groupRows[row] {
+				s := siteGroupStyle
+				return &s
+			}
+			return nil
+		},
+	)
 }
 
 func (m *Model) initSiteHuhForm() tea.Cmd {

internal/tui/tab_users.go

@@ -6,26 +6,6 @@ import (
 
 	tea "github.com/charmbracelet/bubbletea"
 	"github.com/charmbracelet/huh"
-	"github.com/charmbracelet/lipgloss"
-	"github.com/charmbracelet/lipgloss/table"
-)
-
-var (
-	userHeaderStyle = lipgloss.NewStyle().
-			Foreground(lipgloss.Color("#7D56F4")).
-			Bold(true).
-			Padding(0, 1)
-
-	userCellStyle = lipgloss.NewStyle().Padding(0, 1)
-
-	userSelectedStyle = lipgloss.NewStyle().
-				Padding(0, 1).
-				Bold(true).
-				Foreground(lipgloss.Color("#ffffff")).
-				Background(lipgloss.Color("#3b3b5c"))
-
-	userBorderStyle = lipgloss.NewStyle().
-			Foreground(lipgloss.Color("#444"))
 )
 
 type userFormData struct {
@@ -53,46 +33,24 @@ func (m Model) viewUsersTab() string {
 		return "\n  No users configured. Press [n] to add one."
 	}
 
-	end := m.tableOffset + m.maxTableRows
+	return m.renderTable(
-	if end > len(m.users) {
+		[]string{"#", "USERNAME", "ROLE", "PUBLIC KEY"},
-		end = len(m.users)
+		len(m.users),
-	}
+		func(start, end int) [][]string {
-
+			var rows [][]string
-	selectedVisual := m.cursor - m.tableOffset
+			for i := start; i < end; i++ {
-
+				u := m.users[i]
-	var rows [][]string
+				rows = append(rows, []string{
-	for i := m.tableOffset; i < end; i++ {
+					fmt.Sprintf("%d", i+1),
-		u := m.users[i]
+					m.zones.Mark(fmt.Sprintf("user-%d", i), limitStr(u.Username, 15)),
-		rows = append(rows, []string{
+					fmtRole(u.Role),
-			fmt.Sprintf("%d", i+1),
+					fmtKey(u.PublicKey),
-			m.zones.Mark(fmt.Sprintf("user-%d", i), limitStr(u.Username, 15)),
+				})
-			fmtRole(u.Role),
-			fmtKey(u.PublicKey),
-		})
-	}
-
-	tableWidth := m.termWidth - 6
-	if tableWidth < 40 {
-		tableWidth = 40
-	}
-
-	t := table.New().
-		Border(lipgloss.RoundedBorder()).
-		BorderStyle(userBorderStyle).
-		Width(tableWidth).
-		Headers("#", "USERNAME", "ROLE", "PUBLIC KEY").
-		Rows(rows...).
-		StyleFunc(func(row, col int) lipgloss.Style {
-			if row == table.HeaderRow {
-				return userHeaderStyle
 			}
-			if row == selectedVisual {
+			return rows
-				return userSelectedStyle
+		},
-			}
+		nil, nil,
-			return userCellStyle
+	)
-		})
-
-	return "\n" + t.Render()
 }
 
 func (m *Model) initUserHuhForm() tea.Cmd {

internal/tui/table_helpers.go

@@ -0,0 +1,75 @@
+package tui
+
+import (
+	"github.com/charmbracelet/lipgloss"
+	"github.com/charmbracelet/lipgloss/table"
+)
+
+var (
+	tableHeaderStyle = lipgloss.NewStyle().
+				Foreground(lipgloss.Color("#7D56F4")).
+				Bold(true).
+				Padding(0, 1)
+
+	tableCellStyle = lipgloss.NewStyle().Padding(0, 1)
+
+	tableSelectedStyle = lipgloss.NewStyle().
+				Padding(0, 1).
+				Bold(true).
+				Foreground(lipgloss.Color("#ffffff")).
+				Background(lipgloss.Color("#3b3b5c"))
+
+	tableBorderStyle = lipgloss.NewStyle().
+				Foreground(lipgloss.Color("#444"))
+)
+
+type StyleOverride func(row, col int) *lipgloss.Style
+
+func (m Model) renderTable(headers []string, items int, buildRows func(start, end int) [][]string, colWidths []int, styleOverride StyleOverride) string {
+	if items == 0 {
+		return ""
+	}
+
+	end := m.tableOffset + m.maxTableRows
+	if end > items {
+		end = items
+	}
+
+	selectedVisual := m.cursor - m.tableOffset
+	rows := buildRows(m.tableOffset, end)
+
+	tableWidth := m.termWidth - 6
+	if tableWidth < 40 {
+		tableWidth = 40
+	}
+
+	t := table.New().
+		Border(lipgloss.RoundedBorder()).
+		BorderStyle(tableBorderStyle).
+		Width(tableWidth).
+		Headers(headers...).
+		Rows(rows...).
+		StyleFunc(func(row, col int) lipgloss.Style {
+			if row == table.HeaderRow {
+				return tableHeaderStyle
+			}
+			if styleOverride != nil {
+				if s := styleOverride(row, col); s != nil {
+					if col < len(colWidths) && colWidths[col] > 0 {
+						return s.Width(colWidths[col])
+					}
+					return *s
+				}
+			}
+			base := tableCellStyle
+			if row == selectedVisual {
+				base = tableSelectedStyle
+			}
+			if col < len(colWidths) && colWidths[col] > 0 {
+				base = base.Width(colWidths[col])
+			}
+			return base
+		})
+
+	return "\n" + t.Render()
+}

internal/tui/tui.go

@@ -346,11 +346,11 @@ func (m Model) Update(msg tea.Msg) (tea.Model, tea.Cmd) {
 }
 
 func (m *Model) handleClick(msg tea.MouseMsg) (tea.Model, tea.Cmd) {
-	maxTabs := 3
+	tabCount := 3
-	if !m.isAdmin {
+	if m.isAdmin {
-		maxTabs = 2
+		tabCount = 4
 	}
-	for i := 0; i <= maxTabs; i++ {
+	for i := 0; i < tabCount; i++ {
 		if m.zones.Get(fmt.Sprintf("tab-%d", i)).InBounds(msg) {
 			m.switchTab(i)
 			return m, nil
@@ -477,6 +477,19 @@ func (m *Model) refreshData() {
 		}
 	}
 	m.logViewport.SetContent(strings.Join(monitor.GetLogs(), "\n"))
+
+	listLen := len(m.sites)
+	if m.currentTab == 1 {
+		listLen = len(m.alerts)
+	} else if m.currentTab == 3 {
+		listLen = len(m.users)
+	}
+	if listLen > 0 && m.cursor >= listLen {
+		m.cursor = listLen - 1
+	}
+	if m.cursor < m.tableOffset {
+		m.tableOffset = m.cursor
+	}
 }
 
 func (m *Model) submitForm() {