update applying current ai insight from dashboard-cpsp

utils/kpiStock.ts

@@ -0,0 +1,10 @@
+/**
+ * KPI.chicken_life = DOC − cumulative mortality (excludes harvest).
+ * Stock akhir (in-house remaining) = chicken_life − harvest_total.
+ */
+export function stockAkhirFromKpi(
+  kpi: { chicken_life?: number | null; harvest_total?: number | null } | null | undefined
+): number | null {
+  if (kpi?.chicken_life == null) return null;
+  return Math.max(0, kpi.chicken_life - (kpi.harvest_total ?? 0));
+}