third party update , optional body is done

src/claim-request-management/fanavaran-claim-product.ts

@@ -46,6 +46,35 @@ export function fanavaranClaimsBaseUrl(
   return `${FANAVARAN_CLAIMS_HOST}/${fanavaranClaimsResourcePath(product)}`;
 }
 
+export type FanavaranClaimStage = "damage-case" | "attachments" | "expertise";
+
+/** Hull (بدنه) has no GEN.12 dmg-cases resource. Proven 2026-09-15: Feature:url(.../vehicle-hull-claims/{id}/dmg-cases) not found. Files and expertise do exist. */
+export const FANAVARAN_HULL_NO_DAMAGE_CASE_REASON =
+  "Fanavaran vehicle-hull-claims has no dmg-cases resource. Hull is first-party (one damaged vehicle on the base claim). Continue with files and expertise.";
+
+export function fanavaranHasDamageCaseStage(
+  product: FanavaranClaimProduct,
+): boolean {
+  return product === "third-party";
+}
+
+export function fanavaranClaimStageUrl(
+  product: FanavaranClaimProduct,
+  stage: FanavaranClaimStage,
+  claimId: number | string,
+): string | null {
+  if (stage === "damage-case" && !fanavaranHasDamageCaseStage(product)) {
+    return null;
+  }
+  const suffix =
+    stage === "damage-case"
+      ? "dmg-cases"
+      : stage === "attachments"
+        ? "files"
+        : "expertise";
+  return `${fanavaranClaimsBaseUrl(product)}/${claimId}/${suffix}`;
+}
+
 export function fanavaranInsuranceLineIdForProduct(
   product: FanavaranClaimProduct,
 ): number {