refactor: consolidate duplicated code across web and API packages

- Extract shared render helpers (vacation blocks, range overlay, overbooking blink) into renderHelpers.tsx
- Centralize status badge styles and vacation color maps into status-styles.ts
- Extract dragMath.ts utility from useTimelineDrag for reuse
- Split useInvalidatePlanningViews into useInvalidateTimeline (4 queries) + useInvalidatePlanningViews (8 queries)
- Adopt findUniqueOrThrow() and Prisma select constants across API routers
- Add shared fmtEur() helper for API-side money formatting
- Wrap TimelineResourcePanel and TimelineProjectPanel with React.memo
- Fix pre-existing TS2589 deep type errors in TeamCalendar and VacationModal
- 38 files changed, reducing ~400 lines of duplicated code

Co-Authored-By: claude-flow <ruv@ruv.net>

apps/web/src/components/projects/ProjectDemandsTable.tsx

@@ -2,7 +2,7 @@
 
 import { useState } from "react";
 import { useRouter } from "next/navigation";
-import { formatDate } from "~/lib/format.js";
+import { formatCents, formatDate } from "~/lib/format.js";
 import { InfoTooltip } from "~/components/ui/InfoTooltip.js";
 import { FillOpenDemandModal } from "~/components/allocations/FillOpenDemandModal.js";
 import { AllocationModal } from "~/components/allocations/AllocationModal.js";
@@ -132,11 +132,11 @@ export function ProjectDemandsTable({ demands, project }: ProjectDemandsTablePro
                       return (
                         <div>
                           <div className="text-gray-900 dark:text-gray-100">
-                            {(demand.budgetCents! / 100).toLocaleString("de-DE", { minimumFractionDigits: 2 })} EUR
+                            {formatCents(demand.budgetCents!)} EUR
                           </div>
                           <div className={`text-xs ${remainCents < 0 ? "text-red-500" : "text-gray-400"}`}>
-                            {bookedCents > 0 ? `${(bookedCents / 100).toLocaleString("de-DE", { minimumFractionDigits: 2 })} booked` : ""}
-                            {remainCents < 0 ? ` (${(Math.abs(remainCents) / 100).toLocaleString("de-DE", { minimumFractionDigits: 2 })} over)` : ""}
+                            {bookedCents > 0 ? `${formatCents(bookedCents)} booked` : ""}
+                            {remainCents < 0 ? ` (${formatCents(Math.abs(remainCents))} over)` : ""}
                           </div>
                         </div>
                       );