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/vacations/VacationCalendar.tsx

@@ -2,6 +2,7 @@
 
 import { useState } from "react";
 import { VacationStatus, VacationType } from "@planarchy/shared";
+import { VACATION_CALENDAR_COLORS } from "~/lib/status-styles.js";
 
 interface VacationEntry {
   id: string;
@@ -18,13 +19,6 @@ interface VacationCalendarProps {
   initialMonth?: number; // 0-indexed
 }
 
-const TYPE_COLOR: Record<string, string> = {
-  ANNUAL: "bg-brand-500",
-  SICK: "bg-red-400",
-  PUBLIC_HOLIDAY: "bg-emerald-400",
-  OTHER: "bg-purple-400",
-};
-
 const STATUS_OPACITY: Record<string, string> = {
   APPROVED: "opacity-100",
   PENDING: "opacity-60",
@@ -145,7 +139,7 @@ export function VacationCalendar({ vacations, year = new Date().getFullYear(), i
               </span>
               <div className="space-y-0.5">
                 {dayVacations.slice(0, 3).map((v) => {
-                  const colorClass = TYPE_COLOR[v.type] ?? "bg-gray-400";
+                  const colorClass = VACATION_CALENDAR_COLORS[v.type] ?? "bg-gray-400";
                   const opacityClass = STATUS_OPACITY[v.status] ?? "opacity-100";
                   const name = v.resource?.displayName ?? "—";
                   return (
@@ -169,7 +163,7 @@ export function VacationCalendar({ vacations, year = new Date().getFullYear(), i
 
       {/* Legend */}
       <div className="px-4 py-2 border-t border-gray-100 dark:border-gray-700 flex gap-4 flex-wrap">
-        {Object.entries(TYPE_COLOR).map(([type, color]) => (
+        {Object.entries(VACATION_CALENDAR_COLORS).map(([type, color]) => (
           <span key={type} className="flex items-center gap-1.5 text-xs text-gray-500 dark:text-gray-400">
             <span className={`${color} w-3 h-3 rounded-sm inline-block`} />
             {type.replace("_", " ")}