feat(supply): unit-centric fit-out & overview — per-unit fit-out, editable demand budget, multi-unit price/availability

- domain/unit: optional per-unit fitOut override (falls back to property.hardFacts.fitOut)
- matchSyncService: pre-market unit scored with its own fitOut; matchCardAdapter prefers unit fitOut
- PreMarketUnitGrid/PreMarketPanel: per-unit Ausbaustandard override in the release list (default "Wie Objekt")
- PropertyDetailOverview: edit/read "Wer baut aus?" for existing listings (SHELL/BASIC), central FIT_OUT_LABELS
- Phase 1 unit-centric overview: header shows area+count, price as range, "Verfügbar ab → pro Einheit"; unit table shows per-unit price + availability; "Objekt & Lage" labels marked as object-defaults for multi-unit
- NeedExtendedRequirements: "Eigenes Ausbaubudget" only shown when min fit-out set + clearer helper text
- UnitStructurePanel: spin-off prefill carries fitOutByLandlord

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

src/domain/unit.ts

@@ -17,6 +17,9 @@ export interface PropertyUnit {
   areaSqm: number
   available: boolean
   rentPricePerSqm?: number  // annual CHF/m²; falls back to property.rentPricePerSqm
+  // Unit-level fit-out override — falls back to property.hardFacts.fitOut when unset.
+  // Relevant for pre-market, where units of one property are matched individually.
+  fitOut?: 'SHELL' | 'BASIC' | 'FULL' | 'PREMIUM'
   leases?: Lease[]          // Mietverträge — current, historical, future
   /** @deprecated Use leases[].tenant.companyName */
   currentTenant?: string