fix(stacks): RestartStack now uses up -d with env vars

Previously used bare "docker compose restart" which doesn't inject
env vars or pick up template changes. Now matches StartStack behavior.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

controller/internal/stacks/manager.go

@@ -450,14 +450,18 @@ func (m *Manager) RestartStack(name string) error {
 	m.logger.Printf("[INFO] Restarting stack: %s", name)
 	start := time.Now()
 	dir := filepath.Dir(stack.ComposePath)
+	env := m.stackEnv(dir)
 
-	if _, err := m.composeExec(dir, "restart"); err != nil {
+	// Use "up -d" instead of bare "restart" so that env vars from app.yaml
+	// are injected and any template changes (new images, healthchecks) are
+	// picked up. Plain "docker compose restart" only sends SIGTERM+start
+	// to existing containers without re-reading the compose file or env.
+	if _, err := m.composeExecCustomEnv(dir, env, "up", "-d"); err != nil {
 		m.logger.Printf("[ERROR] Stack %s restart failed after %.1fs: %v", name, time.Since(start).Seconds(), err)
 		return fmt.Errorf("restarting stack %s: %w", name, err)
 	}
 
 	m.logger.Printf("[INFO] Stack %s restarted successfully (took %.1fs)", name, time.Since(start).Seconds())
-	env := m.stackEnv(dir)
 	m.logPostStartStatus(name, dir, env)
 	return m.RefreshStatus()
 }