feat: ACL labels from environment variables (#422)

* feat: add LabelService to retrieve application labels from environment variables

* feat: allow usage of labels from docker and env variables simultaneously

Prioritize labels from environment variables over labels from docker
labels

* fix: handle error returned by label_serive.go/LoadLabels

see https://github.com/steveiliop56/tinyauth/pull/422#discussion_r2443443032

* refactor(label_service): use simple loop instead of slices.ContainsFunc to avoid experimental slices package
see https://github.com/steveiliop56/tinyauth/pull/422#pullrequestreview-3354632045

* refactor: merge acl logic into one service

---------

Co-authored-by: Stavros <steveiliop56@gmail.com>

internal/bootstrap/app_bootstrap.go

@@ -139,12 +139,14 @@ func (app *BootstrapApp) Setup() error {
 
 	// Create services
 	dockerService := service.NewDockerService()
+	aclsService := service.NewAccessControlsService(dockerService)
 	authService := service.NewAuthService(authConfig, dockerService, ldapService, database)
 	oauthBrokerService := service.NewOAuthBrokerService(oauthProviders)
 
-	// Initialize services
+	// Initialize services (order matters)
 	services := []Service{
 		dockerService,
+		aclsService,
 		authService,
 		oauthBrokerService,
 	}
@@ -246,7 +248,7 @@ func (app *BootstrapApp) Setup() error {
 
 	proxyController := controller.NewProxyController(controller.ProxyControllerConfig{
 		AppURL: app.config.AppURL,
-	}, apiRouter, dockerService, authService)
+	}, apiRouter, aclsService, authService)
 
 	userController := controller.NewUserController(controller.UserControllerConfig{
 		CookieDomain: cookieDomain,