fix: remove FUTURE_SIGNAL from supply availability filter

FUTURE_SIGNAL is a demand/AI market intelligence concept — it applies
to properties not in the manager's portfolio. Own properties can only
be AVAILABLE_NOW, AVAILABLE_SOON, or OCCUPIED.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

src/components/supply/PropertyFilterBar.tsx

@@ -33,7 +33,14 @@ const SORT_OPTIONS = [
 ] as const
 
 const ALL_ASSET_TYPES = Object.values(AssetType)
-const ALL_AVAILABILITY = Object.values(AvailabilityStatus)
+
+// Supply-side only: FUTURE_SIGNAL is a demand/AI concept (market intelligence for unknown properties)
+// A property manager's own inventory can only be in one of these three states
+const SUPPLY_AVAILABILITY_STATUSES = [
+  AvailabilityStatus.AVAILABLE_NOW,
+  AvailabilityStatus.AVAILABLE_SOON,
+  AvailabilityStatus.OCCUPIED,
+] as const
 
 export function PropertyFilterBar({ filters, onFiltersChange }: PropertyFilterBarProps) {
   const isActive =
@@ -95,7 +102,7 @@ export function PropertyFilterBar({ filters, onFiltersChange }: PropertyFilterBa
             sx={{ minWidth: 160 }}
           >
             <MenuItem value="">Verfügbarkeit (alle)</MenuItem>
-            {ALL_AVAILABILITY.map(s => (
+            {SUPPLY_AVAILABILITY_STATUSES.map(s => (
               <MenuItem key={s} value={s}>{getAvailabilityLabel(s)}</MenuItem>
             ))}
           </Select>