feat(MemberOrder): add budget field to MemberOrder and MemberOrderHistory models

- Introduced a new budget field in both MemberOrder and MemberOrderHistory models to track budget amounts.
- Updated memberOrderService to handle budget in serialization and normalization processes.
- Enhanced OrdersPanel component to include budget input and display in the UI.
- Added German localization for the new budget term to ensure consistency across languages.

backend/services/memberOrderService.js

@@ -20,10 +20,12 @@ const serializeOrder = (order) => {
   const plain = typeof order.toJSON === 'function' ? order.toJSON() : { ...order };
   const cost = normalizeAmount(plain.cost);
   const paidAmount = normalizeAmount(plain.paidAmount);
+  const budget = normalizeAmount(plain.budget);
   return {
     ...plain,
     cost,
     paidAmount,
+    budget,
     openAmount: Math.max(0, Number((cost - paidAmount).toFixed(2)))
   };
 };
@@ -32,10 +34,12 @@ const serializeHistoryEntry = (entry) => {
   const plain = typeof entry.toJSON === 'function' ? entry.toJSON() : { ...entry };
   const cost = normalizeAmount(plain.cost);
   const paidAmount = normalizeAmount(plain.paidAmount);
+  const budget = normalizeAmount(plain.budget);
   return {
     ...plain,
     cost,
     paidAmount,
+    budget,
     openAmount: Math.max(0, Number((cost - paidAmount).toFixed(2)))
   };
 };
@@ -64,7 +68,8 @@ class MemberOrderService {
       status: order.status,
       changedAt: new Date(),
       cost: normalizeAmount(order.cost),
-      paidAmount: normalizeAmount(order.paidAmount)
+      paidAmount: normalizeAmount(order.paidAmount),
+      budget: normalizeAmount(order.budget)
     }, transaction ? { transaction } : undefined);
   }
 
@@ -105,6 +110,7 @@ class MemberOrderService {
     const status = ORDER_STATUSES.includes(payload?.status) ? payload.status : 'requested';
     const cost = normalizeAmount(payload?.cost);
     const paidAmount = normalizeAmount(payload?.paidAmount);
+    const budget = normalizeAmount(payload?.budget);
 
     if (!item) {
       return {
@@ -121,7 +127,8 @@ class MemberOrderService {
       orderDate: new Date(),
       statusDate: new Date(),
       cost,
-      paidAmount
+      paidAmount,
+      budget
     });
 
     await this._createHistorySnapshot(order);
@@ -171,6 +178,7 @@ class MemberOrderService {
     const nextStatus = payload?.status && ORDER_STATUSES.includes(payload.status) ? payload.status : order.status;
     const nextCost = payload?.cost != null ? normalizeAmount(payload.cost) : normalizeAmount(order.cost);
     const nextPaidAmount = payload?.paidAmount != null ? normalizeAmount(payload.paidAmount) : normalizeAmount(order.paidAmount);
+    const nextBudget = payload?.budget != null ? normalizeAmount(payload.budget) : normalizeAmount(order.budget);
 
     if (nextItem && nextItem !== order.item) {
       order.item = nextItem;
@@ -189,6 +197,10 @@ class MemberOrderService {
       order.paidAmount = nextPaidAmount;
       changed = true;
     }
+    if (nextBudget !== normalizeAmount(order.budget)) {
+      order.budget = nextBudget;
+      changed = true;
+    }
 
     if (!changed) {
       const existing = await this.getMemberOrders(userToken, clubId, memberId);