fix(order): reconcile subscriptions and grant device trials

internal/logic/auth/trialEmailWhitelist.go

@@ -54,12 +54,19 @@ func ShouldGrantTrialForEmail(register config.RegisterConfig, email string) bool
 	return true
 }
 
+// IsTrialConfigReady verifies that trial auto-grant has all required config.
+func IsTrialConfigReady(register config.RegisterConfig) bool {
+	return register.EnableTrial &&
+		register.TrialSubscribe > 0 &&
+		register.TrialTime > 0 &&
+		strings.TrimSpace(register.TrialTimeUnit) != ""
+}
+
 // ShouldAutoGrantTrialOnPublicEmailFlows defines whether browser/email-originated
-// flows may auto-create a trial subscription. The current policy disables trial
-// creation for email registration, email login auto-register, OAuth-with-email,
-// and email binding/verification to avoid abuse through public email channels.
+// flows may auto-create a trial subscription. Email-specific abuse protection
+// is still handled by ShouldGrantTrialForEmail and NormalizedEmailHasTrial.
 func ShouldAutoGrantTrialOnPublicEmailFlows(register config.RegisterConfig) bool {
-	return false
+	return IsTrialConfigReady(register)
 }
 
 // IsDisposableAlias detects Gmail dot trick and + alias abuse.