feat(frontend): ClaimDetail type + api.getClaimDetail

src/lib/api.ts

@@ -23,6 +23,7 @@
 
 import type {
   Ack,
+  ClaimDetail,
   ClaimOutput,
   ClaimPayment,
   Envelope,
@@ -451,6 +452,29 @@ async function listClaims<T = unknown>(
   return (await res.json()) as PaginatedResponse<T>;
 }
 
+/**
+ * Fetch one claim with the full SP4 detail-drawer context (header, state,
+ * parties, validation, service lines, diagnoses, raw segments, recent
+ * ``stateHistory``, and a populated ``matchedRemittance`` when paired).
+ *
+ * Drives ``GET /api/claims/{claim_id}``. Throws ``ApiError`` on non-2xx —
+ * including 404, which the spec §3.4 calls out as a distinct "claim
+ * doesn't exist" state in the drawer (separate from a transient fetch
+ * failure). Callers should branch on ``error.status === 404`` to render
+ * the not-found state instead of the generic error toast.
+ */
+async function getClaimDetail(id: string): Promise<ClaimDetail> {
+  if (!isConfigured) throw notConfiguredError();
+  const res = await fetch(joinUrl(`/api/claims/${encodeURIComponent(id)}`), {
+    headers: { Accept: "application/json" },
+  });
+  if (!res.ok) {
+    const detail = await readErrorBody(res);
+    throw new ApiError(res.status, detail || res.statusText);
+  }
+  return (await res.json()) as ClaimDetail;
+}
+
 async function listRemittances<T = unknown>(
   params: ListRemittancesParams
 ): Promise<PaginatedResponse<T>> {
@@ -649,6 +673,7 @@ export const api = {
   listBatches,
   getBatch,
   listClaims,
+  getClaimDetail,
   listRemittances,
   getRemittance,
   listProviders,