feat(agents): Add identity and soul template fields to board creation

frontend/src/lib/api-base.ts

@@ -0,0 +1,11 @@
+export function getApiBaseUrl(): string {
+  const raw = process.env.NEXT_PUBLIC_API_URL;
+  if (!raw) {
+    throw new Error("NEXT_PUBLIC_API_URL is not set.");
+  }
+  const normalized = raw.replace(/\/+$/, "");
+  if (!normalized) {
+    throw new Error("NEXT_PUBLIC_API_URL is invalid.");
+  }
+  return normalized;
+}