Adding repo after 2 days of vibecoding

server/worldSeed.js

@@ -0,0 +1,17 @@
+/**
+ * One world seed per UTC-aligned period: floor(utcUnixSeconds / rotationSeconds).
+ * Changing the slot triggers a full grid wipe on the server.
+ */
+export function computeWorldSeedState(rotationSeconds) {
+  const rot = Math.max(60, Math.floor(rotationSeconds));
+  const nowSec = Math.floor(Date.now() / 1000);
+  const slot = Math.floor(nowSec / rot);
+  const periodStart = slot * rot;
+  const periodEnd = periodStart + rot;
+  return {
+    worldSeed: `swg-${slot}`,
+    seedSlot: slot,
+    seedPeriodEndsAtUtc: new Date(periodEnd * 1000).toISOString(),
+    seedPeriodStartsAtUtc: new Date(periodStart * 1000).toISOString(),
+  };
+}