Add interactive Markdown checklist toggles in the ticket preview.

Co-authored-by: Cursor <cursoragent@cursor.com>

internal/ui/views/markdown.go

@@ -1,11 +1,15 @@
 package views
 
 import (
+	"strings"
 	"sync"
 
 	"github.com/charmbracelet/glamour"
 	"github.com/charmbracelet/glamour/styles"
+	"github.com/charmbracelet/lipgloss"
 	"github.com/muesli/termenv"
+
+	"task/internal/ticket"
 )
 
 type mdCacheKey struct {
@@ -79,6 +83,78 @@ func getRenderer(width int) (*glamour.TermRenderer, error) {
 	return r, nil
 }
 
+// RenderDescription renders ticket Markdown with interactive task-list items.
+// checklistCursor is the 0-based index among checkboxes (highlight); ignored when
+// there are none.
+func RenderDescription(src string, width int, checklistCursor int) string {
+	if strings.TrimSpace(src) == "" {
+		return ""
+	}
+	boxes := ticket.ListCheckboxes(src)
+	if len(boxes) == 0 {
+		return RenderMarkdown(src, width)
+	}
+
+	boxByLine := make(map[int]int, len(boxes))
+	for i, b := range boxes {
+		boxByLine[b.Line] = i
+	}
+
+	lines := strings.Split(src, "\n")
+	var parts []string
+	var mdBuf []string
+	flushMD := func() {
+		if len(mdBuf) == 0 {
+			return
+		}
+		block := strings.Join(mdBuf, "\n")
+		if strings.TrimSpace(block) != "" {
+			parts = append(parts, RenderMarkdown(block, width))
+		}
+		mdBuf = nil
+	}
+
+	for i, line := range lines {
+		if bi, ok := boxByLine[i]; ok {
+			flushMD()
+			parts = append(parts, renderCheckboxLine(boxes[bi], bi == checklistCursor, width))
+			continue
+		}
+		mdBuf = append(mdBuf, line)
+	}
+	flushMD()
+	if len(parts) == 0 {
+		return ""
+	}
+	return lipgloss.JoinVertical(lipgloss.Left, parts...)
+}
+
+func renderCheckboxLine(box ticket.Checkbox, selected bool, width int) string {
+	// ASCII markers — widely supported; bold + padding reads a notch bigger.
+	mark := "[ ]"
+	if box.Checked {
+		mark = "[x]"
+	}
+	prefix := "  "
+	if selected {
+		prefix = "> "
+	}
+	label := strings.TrimSpace(box.Text)
+	avail := max(10, width) - lipgloss.Width(prefix+mark+" ")
+	label = truncateOneLine(label, avail)
+
+	markStyle := lipgloss.NewStyle().Bold(true)
+	labelStyle := lipgloss.NewStyle()
+	if selected {
+		markStyle = markStyle.Foreground(lipgloss.Color("39"))
+		labelStyle = labelStyle.Bold(true).Foreground(lipgloss.Color("39"))
+	} else if box.Checked {
+		labelStyle = labelStyle.Faint(true)
+	}
+	line := prefix + markStyle.Render(mark) + " " + labelStyle.Render(label)
+	return lipgloss.NewStyle().Width(max(10, width)).Render(line)
+}
+
 // ClearMarkdownCache drops cached renders (e.g. after theme change).
 func ClearMarkdownCache() {
 	mdMu.Lock()