update kpi mortality card to change color based on the status

utils/mortality.ts

@@ -0,0 +1,49 @@
+import type { KpiStatus } from '../components/KpiCard.tsx';
+
+/**
+ * Daily mortality % of DOC thresholds (manager operational rules):
+ * - <= 0.05%: Normal / OK (green)
+ * - > 0.05% and < 0.10%: Warning (yellow)
+ * - >= 0.10%: Critical (red)
+ */
+export const DAILY_MORTALITY_DOC_THRESHOLDS = {
+  warning_pct: 0.05,
+  critical_pct: 0.1,
+} as const;
+
+/**
+ * Calculates daily mortality percentage relative to initial DOC count.
+ */
+export function getDailyMortalityPct(
+  mortalityToday: number | null | undefined,
+  docInCount: number | null | undefined
+): number | null {
+  if (mortalityToday == null || docInCount == null || docInCount <= 0) {
+    return null;
+  }
+  return (mortalityToday / docInCount) * 100;
+}
+
+/**
+ * Evaluates the KPI status for daily mortality based on DOC thresholds.
+ * - 'na' when data is unavailable
+ * - 'critical' when daily mortality >= 0.10%
+ * - 'warning' when daily mortality > 0.05%
+ * - 'ok' when daily mortality <= 0.05%
+ */
+export function getDailyMortalityStatus(
+  mortalityToday: number | null | undefined,
+  docInCount: number | null | undefined
+): KpiStatus {
+  if (mortalityToday == null) return 'na';
+  if (docInCount == null || docInCount <= 0) return 'ok';
+
+  const dailyPct = (mortalityToday / docInCount) * 100;
+  if (dailyPct >= DAILY_MORTALITY_DOC_THRESHOLDS.critical_pct) {
+    return 'critical';
+  }
+  if (dailyPct > DAILY_MORTALITY_DOC_THRESHOLDS.warning_pct) {
+    return 'warning';
+  }
+  return 'ok';
+}