feat(flight-finder): implement milestone M2 - report workflow and delivery gates

skills/flight-finder/src/input-validation.ts

@@ -0,0 +1,25 @@
+export function normalizeMarketCountry(
+  value: string | null | undefined
+): string | null | undefined {
+  const cleaned = typeof value === "string" ? value.trim() : undefined;
+  if (!cleaned) {
+    return undefined;
+  }
+
+  const normalized = cleaned.toUpperCase();
+  if (!/^[A-Z]{2}$/.test(normalized)) {
+    throw new Error(
+      `Invalid marketCountry "${value}". Use an ISO 3166-1 alpha-2 uppercase country code such as "TH" or "DE".`
+    );
+  }
+
+  return normalized;
+}
+
+export function isPlausibleEmail(value: string | null | undefined): boolean {
+  if (!value) {
+    return false;
+  }
+
+  return /^[^\s@]+@[^\s@]+\.[^\s@]+$/.test(value);
+}