chore(repo): initialize planarchy workspace

apps/web/src/lib/planningEntryIds.ts

@@ -0,0 +1,9 @@
+type PlanningEntryIdentity = {
+  id: string;
+  entityId?: string | null;
+  sourceAllocationId?: string | null;
+};
+
+export function getPlanningEntryMutationId(entry: PlanningEntryIdentity): string {
+  return entry.entityId ?? entry.sourceAllocationId ?? entry.id;
+}