fix(supply): unit edits now persist + regroup editor + expected price as pre-market KI view

- MockupUnitProvider.update: immutable update (new unit/units/property refs) so React Query detects the change and re-renders — fixes "parking/price edit doesn't take effect"
- UnitFieldsEditor: group Ausbaustandard + Wer-baut-aus + MAB into one "Ausbau" section; conditions (price/availability/parking) on top; removed the plain expected-price field
- PreMarketUnitGrid: expected price is now a KI recommendation view (indexed suggestion + rationale) shown only for released units, with an adjustable override + "Vorschlag übernehmen"

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

src/provider/MockupUnitProvider.ts

@@ -17,11 +17,16 @@ export const MockupUnitProvider: IUnitProvider = {
     return getAllUnits().find(u => u.id === unitId) ?? null
   },
   async update(unitId: string, data: Partial<PropertyUnit>) {
-    for (const prop of propertyStore) {
+    for (let i = 0; i < propertyStore.length; i++) {
+      const prop = propertyStore[i]
       const idx = (prop.units ?? []).findIndex(u => u.id === unitId)
       if (idx === -1) continue
-      prop.units![idx] = { ...prop.units![idx], ...data }
-      return prop.units![idx]
+      // Immutable update: neue Referenzen (Unit, units-Array, Property), damit React Query
+      // die Änderung via Structural-Sharing erkennt und neu rendert.
+      const nextUnits = [...prop.units!]
+      nextUnits[idx] = { ...nextUnits[idx], ...data }
+      propertyStore[i] = { ...prop, units: nextUnits }
+      return nextUnits[idx]
     }
     throw new Error(`Unit ${unitId} not found`)
   },