feat(api): add staff order detail and compliance eligibility

backend/query-api/src/lib/staff-order-eligibility.js

@@ -0,0 +1,39 @@
+function dedupeStrings(values = []) {
+  return [...new Set(
+    values
+      .filter((value) => typeof value === 'string')
+      .map((value) => value.trim())
+      .filter(Boolean)
+  )];
+}
+
+export function dedupeDocumentNames(values = []) {
+  return dedupeStrings(values);
+}
+
+export function buildStaffOrderEligibilityBlockers({
+  hasActiveWorkforce = true,
+  businessBlockReason = null,
+  hasExistingParticipation = false,
+  missingDocumentNames = [],
+} = {}) {
+  const blockers = [];
+
+  if (!hasActiveWorkforce) {
+    blockers.push('Workforce profile is not active');
+  }
+
+  if (businessBlockReason !== null && businessBlockReason !== undefined) {
+    blockers.push(businessBlockReason
+      ? `You are blocked from working for this client: ${businessBlockReason}`
+      : 'You are blocked from working for this client');
+  }
+
+  if (hasExistingParticipation) {
+    blockers.push('You already applied to or booked this order');
+  }
+
+  blockers.push(...dedupeDocumentNames(missingDocumentNames).map((name) => `Missing required document: ${name}`));
+
+  return dedupeStrings(blockers);
+}