feat: add goleak, guard InitRollbar on empty token (#29)

* feat: add goleak test coverage, guard InitRollbar on empty token

- Add goleak.VerifyTestMain to catch goroutine leaks in tests
- Guard InitRollbar with early return when token is empty, preventing
  rollbarInited=true with no token configured

* fix: reset rollbarInited on empty token, bump Go to 1.25.9

Address review: set rollbarInited=false before early return so
re-calling InitRollbar("", env) properly disables Rollbar after
a previous init.

Author: ankurs

go.mod

@@ -1,6 +1,6 @@
 module github.com/go-coldbrew/errors
 
-go 1.25.8
+go 1.25.9
 
 require (
 	github.com/airbrake/gobrake/v5 v5.6.2
@@ -12,6 +12,7 @@ require (
 	go.opentelemetry.io/otel v1.43.0
 	go.opentelemetry.io/otel/sdk v1.43.0
 	go.opentelemetry.io/otel/trace v1.43.0
+	go.uber.org/goleak v1.3.0
 	google.golang.org/grpc v1.79.3
 )
 

goleak_test.go

@@ -0,0 +1,11 @@
+package errors
+
+import (
+	"testing"
+
+	"go.uber.org/goleak"
+)
+
+func TestMain(m *testing.M) {
+	goleak.VerifyTestMain(m)
+}

notifier/notifier.go

@@ -133,6 +133,10 @@ func InitAirbrake(projectID int64, projectKey string) {
 // token: rollbar token
 // env: rollbar environment
 func InitRollbar(token, env string) {
+	if token == "" {
+		rollbarInited = false
+		return
+	}
 	rollbar.SetToken(token)
 	rollbar.SetEnvironment(env)
 	rollbar.SetStackTracer(func(err error) ([]runtime.Frame, bool) {