fix: avoid repeated daily starlanguage refresh

frontend/src/lib/preserve-shallow-equal.ts

@@ -0,0 +1,18 @@
+export function preserveShallowEqual<T extends object>(current: T, next: T): T {
+  if (Object.is(current, next)) return current;
+
+  const currentRecord = current as Record<string, unknown>;
+  const nextRecord = next as Record<string, unknown>;
+  const currentKeys = Object.keys(currentRecord);
+  const nextKeys = Object.keys(nextRecord);
+
+  if (currentKeys.length !== nextKeys.length) return next;
+
+  for (const key of currentKeys) {
+    if (!Object.hasOwn(nextRecord, key) || !Object.is(currentRecord[key], nextRecord[key])) {
+      return next;
+    }
+  }
+
+  return current;
+}