simplify production database configuration

backend/internal/postgres/open_test.go

@@ -37,8 +37,6 @@ func TestOpenPostgresDoesNotProbeBeforeReadiness(t *testing.T) {
 func TestParseConfigIgnoresPostgresTLSSettingsForLocalBackend(t *testing.T) {
 	cfg, err := ParseConfig(env(map[string]string{
 		"ZHINIAN_DATA_BACKEND":           "local",
-		"DATABASE_SSL_MODE":              "verify-full",
-		"DATABASE_CA_CERT_PATH":          "/missing/ca.pem",
 		"DATABASE_POOL_MAX":              "0",
 		"DATABASE_CONNECTION_TIMEOUT_MS": "invalid",
 	}), nil)
@@ -56,7 +54,7 @@ func TestOpenPostgresRejectsInvalidConfiguredTLSMode(t *testing.T) {
 		DatabaseURL: "postgresql://app:secret@db.example/app",
 		SSLMode:     SSLMode("prefer"),
 	})
-	if err == nil || !strings.Contains(err.Error(), "DATABASE_SSL_MODE") {
-		t.Fatalf("Open() error = %v", err)
+	if err == nil || !strings.Contains(err.Error(), "unsupported DATABASE_URL sslmode") {
+		t.Fatalf("Open() error = %v, want DATABASE_URL sslmode error", err)
 	}
 }