feat(timeline): add pulse animation for in-flight drag mutations

Allocation bars that have active optimistic overrides (post-drag,
awaiting server confirmation) now pulse subtly via animate-pulse.
The pending set is derived from the existing optimisticAllocations
map keys, requiring no additional state.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

packages/engine/src/sah/calculator.ts

@@ -5,6 +5,7 @@
  * It is the denominator for chargeability calculations.
  */
 
+import { toIsoDate } from "@capakraken/shared";
 import type { SpainScheduleRule } from "@capakraken/shared";
 
 // ─── Types ──────────────────────────────────────────────────────────────────
@@ -47,11 +48,6 @@ export interface SAHResult {
 
 // ─── Helpers ────────────────────────────────────────────────────────────────
 
-function toISODate(d: Date | string): string {
-  if (typeof d === "string") return d.slice(0, 10);
-  return d.toISOString().slice(0, 10);
-}
-
 function isWeekend(date: Date): boolean {
   const day = date.getUTCDay();
   return day === 0 || day === 6;
@@ -93,8 +89,8 @@ export function getDailyHours(
 export function calculateSAH(input: SAHInput): SAHResult {
   const { dailyWorkingHours, scheduleRules, fte, periodStart, periodEnd, publicHolidays, absenceDays } = input;
 
-  const holidaySet = new Set(publicHolidays.map(toISODate));
-  const absenceSet = new Set(absenceDays.map(toISODate));
+  const holidaySet = new Set(publicHolidays.map(toIsoDate));
+  const absenceSet = new Set(absenceDays.map(toIsoDate));
 
   let calendarDays = 0;
   let weekendDays = 0;