Refactor relay form

frontend/src/lib/relayPlans.ts

@@ -0,0 +1,3 @@
+export const RELAY_PLAN_IDS = ["free", "basic", "growth"] as const
+
+export type RelayPlanId = (typeof RELAY_PLAN_IDS)[number]

frontend/src/lib/slugify.ts

@@ -0,0 +1,9 @@
+export function slugify(value: string) {
+  return value
+    .toLowerCase()
+    .trim()
+    .normalize("NFD")
+    .replace(/[\u0300-\u036f]/g, "")
+    .replace(/[^a-z0-9]+/g, "-")
+    .replace(/^-+|-+$/g, "")
+}