feat: add interactive update check on startup

When starting kctl-tui without a subcommand, check GitHub Releases
for a newer version and prompt the user to update.

- Silent skip for dev builds and network errors
- Prompt: 'Update now? [y/N]'
- On 'y': apply update, then start TUI
- On 'N'/Enter: start TUI immediately

cmd/kctl-tui/main.go

@@ -83,6 +83,8 @@ func main() {
 		}
 	}
 
+	checkForUpdateInteractive(verbose)
+
 	m := newFullModel()
 	p := tea.NewProgram(m, tea.WithAltScreen())
 	if _, err := p.Run(); err != nil {

cmd/kctl-tui/update.go

@@ -4,11 +4,14 @@
 package main
 
 import (
+	"bufio"
 	"context"
 	"fmt"
 	"log"
 	"os"
+	"strings"
 
+	"github.com/Masterminds/semver/v3"
 	"github.com/creativeprojects/go-selfupdate"
 )
 
@@ -29,6 +32,103 @@ func runUpdate(verbose bool) error {
 	fmt.Printf("Current version: %s\n", current)
 	fmt.Println("Checking for updates...")
 
+	rel, err := detectLatest()
+	if err != nil {
+		return fmt.Errorf("failed to check for updates: %w", err)
+	}
+
+	if rel == nil {
+		fmt.Println("Already up-to-date.")
+		return nil
+	}
+
+	fmt.Printf("Found version %s. Updating...\n", rel.Version())
+
+	if err := applyUpdate(rel); err != nil {
+		return fmt.Errorf("update failed: %w", err)
+	}
+
+	fmt.Printf("Updated from %s to %s\n", current, rel.Version())
+	return nil
+}
+
+// checkForUpdateInteractive checks for a new version and prompts the user to update.
+// Returns true if an update was applied.
+func checkForUpdateInteractive(verbose bool) bool {
+	if version == "dev" {
+		return false
+	}
+
+	if verbose {
+		selfupdate.SetLogger(&verboseLogger{})
+	}
+
+	rel, err := detectLatest()
+	if err != nil {
+		// Silently ignore network errors — don't block startup
+		if verbose {
+			fmt.Fprintf(os.Stderr, "Update check failed: %v\n", err)
+		}
+		return false
+	}
+
+	if rel == nil {
+		return false
+	}
+
+	current, _ := semver.NewVersion(version)
+	newVersion := rel.Version()
+
+	if current != nil && !rel.GreaterThan(current.String()) {
+		return false
+	}
+
+	fmt.Printf("New version %s available (current: %s). Update now? [y/N] ", newVersion, version)
+
+	reader := bufio.NewReader(os.Stdin)
+	answer, _ := reader.ReadString('\n')
+	answer = strings.TrimSpace(strings.ToLower(answer))
+
+	if answer != "y" && answer != "yes" {
+		return false
+	}
+
+	fmt.Println("Updating...")
+	if err := applyUpdate(rel); err != nil {
+		fmt.Fprintf(os.Stderr, "Update failed: %v\n", err)
+		return false
+	}
+
+	fmt.Printf("Updated to %s. Starting kctl-tui...\n", newVersion)
+	return true
+}
+
+func detectLatest() (*selfupdate.Release, error) {
+	source, err := selfupdate.NewGitHubSource(selfupdate.GitHubConfig{})
+	if err != nil {
+		return nil, fmt.Errorf("failed to init GitHub source: %w", err)
+	}
+
+	updater, err := selfupdate.NewUpdater(selfupdate.Config{
+		Source: source,
+	})
+	if err != nil {
+		return nil, fmt.Errorf("failed to create updater: %w", err)
+	}
+
+	repo := selfupdate.ParseSlug(githubSlug)
+	rel, found, err := updater.DetectLatest(context.Background(), repo)
+	if err != nil {
+		return nil, err
+	}
+	if !found {
+		return nil, nil
+	}
+
+	return rel, nil
+}
+
+func applyUpdate(rel *selfupdate.Release) error {
 	source, err := selfupdate.NewGitHubSource(selfupdate.GitHubConfig{})
 	if err != nil {
 		return fmt.Errorf("failed to init GitHub source: %w", err)
@@ -41,20 +141,7 @@ func runUpdate(verbose bool) error {
 		return fmt.Errorf("failed to create updater: %w", err)
 	}
 
-	repo := selfupdate.ParseSlug(githubSlug)
-
-	rel, err := updater.UpdateSelf(context.Background(), current, repo)
-	if err != nil {
-		return fmt.Errorf("update failed: %w", err)
-	}
-
-	if rel != nil && rel.Version() != current {
-		fmt.Printf("Updated from %s to %s\n", current, rel.Version())
-	} else {
-		fmt.Println("Already up-to-date.")
-	}
-
-	return nil
+	return updater.UpdateTo(context.Background(), rel, "")
 }
 
 type verboseLogger struct{}

go.mod

@@ -3,6 +3,7 @@ module github.com/skoelle/kctl-tui
 go 1.25.12
 
 require (
+	github.com/Masterminds/semver/v3 v3.5.0
 	github.com/charmbracelet/bubbles v0.21.1
 	github.com/charmbracelet/bubbletea v1.3.10
 	github.com/creativeprojects/go-selfupdate v1.6.0
@@ -12,7 +13,6 @@ require (
 require (
 	code.gitea.io/sdk/gitea v0.23.2 // indirect
 	github.com/42wim/httpsig v1.2.4 // indirect
-	github.com/Masterminds/semver/v3 v3.5.0 // indirect
 	github.com/atotto/clipboard v0.1.4 // indirect
 	github.com/aymanbagabas/go-osc52/v2 v2.0.1 // indirect
 	github.com/charmbracelet/colorprofile v0.4.1 // indirect