feat: add automatic version update checking and notifications

- Add internal/version module for GitHub release checking
- Integrate async version check in Bubble Tea UI
- Display update notification in main interface
- Add version check to --version/-v command output
- Include comprehensive version comparison and error handling
- Add unit tests for version parsing and comparison logic

internal/ui/view.go

@@ -54,6 +54,20 @@ func (m Model) renderListView() string {
 	// Add the ASCII title
 	components = append(components, m.styles.Header.Render(asciiTitle))
 
+	// Add update notification if available (between title and search)
+	if m.updateInfo != nil && m.updateInfo.Available {
+		updateText := fmt.Sprintf("🚀 Update available: %s → %s",
+			m.updateInfo.CurrentVer,
+			m.updateInfo.LatestVer)
+
+		updateStyle := lipgloss.NewStyle().
+			Foreground(lipgloss.Color("10")). // Green color
+			Bold(true).
+			Align(lipgloss.Center) // Center the notification
+
+		components = append(components, updateStyle.Render(updateText))
+	}
+
 	// Add the search bar with the appropriate style based on focus
 	searchPrompt := "Search (/ to focus): "
 	if m.searchMode {
@@ -157,3 +171,30 @@ func (m Model) renderDeleteConfirmation() string {
 
 	return box.Render(raw)
 }
+
+// renderUpdateNotification renders the update notification banner
+func (m Model) renderUpdateNotification() string {
+	if m.updateInfo == nil || !m.updateInfo.Available {
+		return ""
+	}
+
+	// Create the notification message
+	message := fmt.Sprintf("🚀 Update available: %s → %s",
+		m.updateInfo.CurrentVer,
+		m.updateInfo.LatestVer)
+
+	// Add release URL if available
+	if m.updateInfo.ReleaseURL != "" {
+		message += fmt.Sprintf(" • View release: %s", m.updateInfo.ReleaseURL)
+	}
+
+	// Style the notification with a bright color to make it stand out
+	notificationStyle := lipgloss.NewStyle().
+		Foreground(lipgloss.Color("#00FF00")). // Bright green
+		Bold(true).
+		Padding(0, 1).
+		Border(lipgloss.RoundedBorder()).
+		BorderForeground(lipgloss.Color("#00AA00")) // Darker green border
+
+	return notificationStyle.Render(message)
+}