Energie-Bonus aufgeteilt in Sofort + Neukunden

EnergyContractDetails.bonus war ein einzelnes Feld. Strom-/Gas-
Verträge haben aber typischerweise zwei Boni (Sofort beim Wechsel
+ Neukunden-Bonus nach 12 Monaten), die getrennt verbucht werden
müssen.

Migration 20260524100000_split_energy_bonus:
- ADD COLUMN IF NOT EXISTS instantBonus, newCustomerBonus
- bestehende `bonus`-Werte → instantBonus (Annahme: Sofort)
- DROP COLUMN IF EXISTS bonus

UI:
- ContractForm zeigt zwei Input-Felder
- Detail-Ansicht zeigt beide einzeln + Gesamtbonus
- Kostenvorschau listet beide einzeln, dann Gesamt, dann effektive
  Jahreskosten

Cost-Calc: calculateCosts() bekommt beide Boni; CostCalculation
liefert instantBonus, newCustomerBonus, totalBonus.

PDF-Template: drei neue Variablen energyDetails.instantBonus,
.newCustomerBonus, .totalBonus.

Live-verifiziert auf dev: PUT mit beiden Werten → DB persistiert,
GET liefert zurueck.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

frontend/src/pages/contracts/ContractDetail.tsx

@@ -609,7 +609,8 @@ function EnergyConsumptionCalculation({
   basePrice,
   unitPrice,
   unitPriceNt,
-  bonus,
+  instantBonus,
+  newCustomerBonus,
   hasMeter,
   contractMeters,
 }: {
@@ -619,7 +620,8 @@ function EnergyConsumptionCalculation({
   endDate?: string;
   basePrice?: number;
   unitPrice?: number;
-  bonus?: number;
+  instantBonus?: number;
+  newCustomerBonus?: number;
   unitPriceNt?: number;
   hasMeter?: boolean;
   contractMeters?: ContractMeter[];
@@ -656,7 +658,7 @@ function EnergyConsumptionCalculation({
   const htKwh = consumption?.consumptionHt ?? consumption?.consumptionKwh ?? 0;
   const ntKwh = consumption?.consumptionNt;
   const costs = consumption && consumption.consumptionKwh > 0
-    ? calculateCosts(htKwh, basePrice, unitPrice, bonus, ntKwh, unitPriceNt)
+    ? calculateCosts(htKwh, basePrice, unitPrice, instantBonus, ntKwh, unitPriceNt, newCustomerBonus)
     : null;
 
   const canCalculate = consumption && (consumption.type === 'exact' || consumption.type === 'projected');
@@ -780,12 +782,24 @@ function EnergyConsumptionCalculation({
                     <span className="font-mono">{formatNumber(costs.annualTotalCost)} €</span>
                   </div>
                 </div>
-                {/* Bonus */}
-                {costs.bonus != null && costs.bonus > 0 && (
+                {/* Bonus – Sofort + Neukunden einzeln, dann Gesamt */}
+                {costs.totalBonus != null && costs.totalBonus > 0 && (
                   <>
-                    <div className="flex justify-between text-green-600">
-                      <span>Bonus</span>
-                      <span className="font-mono">- {formatNumber(costs.bonus)} €</span>
+                    {costs.instantBonus != null && costs.instantBonus > 0 && (
+                      <div className="flex justify-between text-green-600">
+                        <span>Sofort-Bonus</span>
+                        <span className="font-mono">- {formatNumber(costs.instantBonus)} €</span>
+                      </div>
+                    )}
+                    {costs.newCustomerBonus != null && costs.newCustomerBonus > 0 && (
+                      <div className="flex justify-between text-green-600">
+                        <span>Neukunden-Bonus</span>
+                        <span className="font-mono">- {formatNumber(costs.newCustomerBonus)} €</span>
+                      </div>
+                    )}
+                    <div className="flex justify-between text-green-700 font-medium">
+                      <span>Gesamtbonus</span>
+                      <span className="font-mono">- {formatNumber(costs.totalBonus)} €</span>
                     </div>
                     <div className="border-t border-gray-300 pt-2">
                       <div className="flex justify-between font-semibold">
@@ -2565,10 +2579,25 @@ export default function ContractDetail() {
                 </dd>
               </div>
             )}
-            {c.energyDetails.bonus && (
+            {/* Bonus: Sofort + Neukunden einzeln + Gesamtbonus */}
+            {c.energyDetails.instantBonus != null && c.energyDetails.instantBonus > 0 && (
               <div>
-                <dt className="text-sm text-gray-500">Bonus</dt>
-                <dd>{c.energyDetails.bonus.toLocaleString('de-DE')} €</dd>
+                <dt className="text-sm text-gray-500">Sofort-Bonus</dt>
+                <dd>{c.energyDetails.instantBonus.toLocaleString('de-DE')} €</dd>
+              </div>
+            )}
+            {c.energyDetails.newCustomerBonus != null && c.energyDetails.newCustomerBonus > 0 && (
+              <div>
+                <dt className="text-sm text-gray-500">Neukunden-Bonus</dt>
+                <dd>{c.energyDetails.newCustomerBonus.toLocaleString('de-DE')} €</dd>
+              </div>
+            )}
+            {((c.energyDetails.instantBonus ?? 0) + (c.energyDetails.newCustomerBonus ?? 0)) > 0 && (
+              <div>
+                <dt className="text-sm text-gray-500">Gesamtbonus</dt>
+                <dd className="font-medium">
+                  {((c.energyDetails.instantBonus ?? 0) + (c.energyDetails.newCustomerBonus ?? 0)).toLocaleString('de-DE')} €
+                </dd>
               </div>
             )}
             {c.energyDetails.previousProviderName && (
@@ -2636,7 +2665,8 @@ export default function ContractDetail() {
             basePrice={c.energyDetails.basePrice}
             unitPrice={c.energyDetails.unitPrice}
             unitPriceNt={c.energyDetails.unitPriceNt}
-            bonus={c.energyDetails.bonus}
+            instantBonus={c.energyDetails.instantBonus}
+            newCustomerBonus={c.energyDetails.newCustomerBonus}
             hasMeter={!!c.energyDetails.meter}
             contractMeters={c.energyDetails.contractMeters}
           />