feat(FN-4760): complete Step 2 — add PR checks endpoint and client

Fusion-Task-Id: FN-4760
Fusion-Task-Lineage: 71db4a53-ee59-49f0-a1f7-232954b86660

packages/dashboard/app/api/legacy.ts

@@ -2198,6 +2198,9 @@ export interface PrCheckStatus {
   name: string;
   required: boolean;
   state: string;
+  detailsUrl?: string;
+  startedAt?: string;
+  completedAt?: string;
 }
 
 export interface PrStatusResponse {
@@ -2215,6 +2218,12 @@ export interface PrRefreshResponse {
   automationStatus?: string | null;
 }
 
+export interface PrChecksResponse {
+  checks: PrCheckStatus[];
+  rollup: "success" | "pending" | "failure" | "unknown";
+  lastCheckedAt: string;
+}
+
 export interface PrMetadataResponse {
   title: string;
   body: string;
@@ -2314,6 +2323,11 @@ export function refreshPrStatus(id: string, projectId?: string): Promise<PrRefre
   });
 }
 
+/** Fetch all PR checks for a task */
+export function fetchPrChecks(id: string, projectId?: string): Promise<PrChecksResponse> {
+  return api<PrChecksResponse>(withProjectId(`/tasks/${id}/pr/checks`, projectId));
+}
+
 // --- Issue Management API ---
 
 /** Re-export GitHub badge-related types for convenience */