HH-442: isolate runtime processes and harden shutdown (#90)

* HH-442: isolate runtime processes and harden shutdown

* HH-442: harden worker shutdown races

* HH-442: gate dependency shutdown on active handlers

---------

Co-authored-by: Rogee <rogee@ipao.vip>

backend/cmd/gochat/coverage_test.go

@@ -4,12 +4,26 @@ import (
 	"testing"
 
 	"github.com/gochat/gochat/internal/config"
+	"github.com/stretchr/testify/require"
 )
 
 func TestPrintUsage_Cov1(t *testing.T) {
 	printUsage()
 }
 
+func TestParseServeArgs(t *testing.T) {
+	workerOnly, err := parseServeArgs(nil)
+	require.NoError(t, err)
+	require.False(t, workerOnly)
+
+	workerOnly, err = parseServeArgs([]string{"--worker-only"})
+	require.NoError(t, err)
+	require.True(t, workerOnly)
+
+	_, err = parseServeArgs([]string{"--unknown"})
+	require.EqualError(t, err, `unknown serve option "--unknown"`)
+}
+
 func TestShouldRunSeedMigrations_True_Cov1(t *testing.T) {
 	cfg := &config.Config{Database: config.DatabaseConfig{RunMigrations: true}}
 	result := shouldRunSeedMigrations(cfg)

backend/cmd/gochat/main.go

@@ -35,7 +35,9 @@ func main() {
 	var err error
 	switch cmd {
 	case "serve", "server", "run":
-		err = serve()
+		err = serve(os.Args[2:])
+	case "worker":
+		err = serve([]string{"--worker-only"})
 	case "seed":
 		err = seed()
 	case "init":
@@ -53,13 +55,18 @@ func main() {
 }
 
 func printUsage() {
-	fmt.Println("Usage: gochat [serve|seed|init]")
-	fmt.Println("  serve  Start the GoChat HTTP server")
+	fmt.Println("Usage: gochat [serve [--worker-only]|worker|seed|init]")
+	fmt.Println("  serve   Start the GoChat HTTP server")
+	fmt.Println("  worker  Start background workers without HTTP")
 	fmt.Println("  seed   Create deterministic development/smoke data")
 	fmt.Println("  init   Initialize super admin account (interactive or via flags)")
 }
 
-func serve() error {
+func serve(args []string) error {
+	workerOnly, err := parseServeArgs(args)
+	if err != nil {
+		return err
+	}
 	env := os.Getenv("GOCHAT_ENV")
 	if env == "" {
 		env = "development"
@@ -68,9 +75,23 @@ func serve() error {
 	if err != nil {
 		return err
 	}
+	if workerOnly {
+		return application.RunWorker()
+	}
 	return application.Run()
 }
 
+func parseServeArgs(args []string) (bool, error) {
+	workerOnly := false
+	for _, arg := range args {
+		if arg != "--worker-only" {
+			return false, fmt.Errorf("unknown serve option %q", arg)
+		}
+		workerOnly = true
+	}
+	return workerOnly, nil
+}
+
 func seed() error {
 	env := os.Getenv("GOCHAT_ENV")
 	if env == "" {