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>

apps/web/src/components/timeline/TimelineResourcePanel.tsx

@@ -520,6 +520,7 @@ function TimelineResourcePanelInner({
                       onInlineEdit,
                       scrollLeft,
                       containerWidth,
+                      optimisticAllocations.size > 0 ? new Set(optimisticAllocations.keys()) : undefined,
                     )}
                 {filters.showVacations &&
                   renderVacationBlocks(
@@ -628,6 +629,7 @@ function renderAllocBlocksFromData(
   onInlineEdit?: (allocationId: string, initialValues: { startDate: Date; endDate: Date; hoursPerDay: number }, barRect: DOMRect) => void,
   scrollLeft = 0,
   containerWidth = 1200,
+  pendingMutationIds?: ReadonlySet<string>,
 ) {
   const OVERSCAN_PX = 10 * CELL_WIDTH;
   const visibleLeft = scrollLeft - OVERSCAN_PX;
@@ -810,6 +812,7 @@ function renderAllocBlocksFromData(
                 ? "opacity-30 z-[10]"
                 : "transition-[opacity] duration-75 z-[10]",
             selectedAllocationSet.has(alloc.id) && "z-20",
+            pendingMutationIds?.has(alloc.id) && !isBeingDragged && "animate-pulse",
           )}
           style={{
             left: segmentLeft + 2,