test(config): cover PAYMENT_TEST_MODE_ENABLED parse + add RAZORPAY_TEST_* to allKeys

allKeys() (env host-state clearer) was missing the RAZORPAY_TEST_* vars and the
new PAYMENT_TEST_MODE_ENABLED flag, so a leaked host env could bleed into config
tests. Add them + a TestLoad_PaymentTestModeEnabled mirroring the other *_ENABLED
flag tests (100%-patch coverage for the new parse branch).

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

Author: claude

internal/config/config_test.go

@@ -40,6 +40,9 @@ func allKeys() []string {
 		"RAZORPAY_PLAN_ID_TEAM", "RAZORPAY_PLAN_ID_HOBBY_ANNUAL",
 		"RAZORPAY_PLAN_ID_HOBBY_PLUS_ANNUAL", "RAZORPAY_PLAN_ID_PRO_ANNUAL",
 		"RAZORPAY_PLAN_ID_GROWTH_ANNUAL", "RAZORPAY_PLAN_ID_TEAM_ANNUAL",
+		"RAZORPAY_TEST_KEY_ID", "RAZORPAY_TEST_KEY_SECRET", "RAZORPAY_TEST_WEBHOOK_SECRET",
+		"RAZORPAY_TEST_PLAN_ID_HOBBY", "RAZORPAY_TEST_PLAN_ID_HOBBY_PLUS",
+		"RAZORPAY_TEST_PLAN_ID_PRO", "PAYMENT_TEST_MODE_ENABLED",
 		"RESEND_API_KEY", "EMAIL_PROVIDER", "BREVO_API_KEY",
 		"EMAIL_FROM_NAME", "EMAIL_FROM_ADDRESS",
 		"GITHUB_CLIENT_ID", "GITHUB_CLIENT_SECRET",
@@ -419,6 +422,21 @@ func TestLoad_ResourceCountCapsEnabled(t *testing.T) {
 	}
 }
 
+func TestLoad_PaymentTestModeEnabled(t *testing.T) {
+	for _, val := range []string{"true", "1", "yes", "TRUE", "  Yes  "} {
+		applyBaselineEnv(t, map[string]string{"PAYMENT_TEST_MODE_ENABLED": val})
+		if !Load().PaymentTestModeEnabled {
+			t.Errorf("PAYMENT_TEST_MODE_ENABLED=%q should enable", val)
+		}
+	}
+	for _, val := range []string{"false", "0", "no", "maybe", ""} {
+		applyBaselineEnv(t, map[string]string{"PAYMENT_TEST_MODE_ENABLED": val})
+		if Load().PaymentTestModeEnabled {
+			t.Errorf("PAYMENT_TEST_MODE_ENABLED=%q should stay disabled (default OFF / fail-closed)", val)
+		}
+	}
+}
+
 func TestLoad_GitHubAppEnabled(t *testing.T) {
 	// When enabling the App, Load() fails closed unless the webhook secret +
 	// private key + app id are present (review HIGH-1), so set them here.