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/db/src/holiday-calendar-seed-data.ts

@@ -1,4 +1,4 @@
-import { getPublicHolidays } from "@capakraken/shared";
+import { getPublicHolidays, toIsoDate } from "@capakraken/shared";
 
 export type HolidayCalendarSeedScope = "COUNTRY" | "STATE" | "CITY";
 
@@ -34,10 +34,6 @@ const COUNTRY_PRIORITY = 10;
 const STATE_PRIORITY = 20;
 const CITY_PRIORITY = 30;
 
-function toIsoDate(date: Date): string {
-  return date.toISOString().slice(0, 10);
-}
-
 function dateUtc(year: number, month: number, day: number): Date {
   return new Date(Date.UTC(year, month - 1, day));
 }