Satsuma: sync part state from CARPARTS/Database, paint, late-installed parts, more controls

- VehicleStateSync also tracks the CARPARTS and Database roots (wear, damaged
  parts, tire wear, oilpan oil, battery charge, carb/ignition settings,
  suspension, odometer); the Satsuma's driver is authoritative for them
- Paint colors (FsmColor) as four float channels (compatible with old servers)
  and applied to the part's material
- FSMs are re-examined when a part is installed/removed (path changes);
  before, anything not on the car at the first scan was never synced
- ControlSync: handbrake, sun visors, seat recline, seat belt, CD player,
  interior light; pending states for controls not found yet
- Late joiners: job/shop values and switch states from the server snapshot;
  P2P host resends all switch states every 15 s

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

ObjectSync.cs

@@ -305,6 +305,7 @@ namespace MSCO
         /// <summary>Besitzer eines Fahrzeugs (nach Wurzelname), NoOwner wenn frei oder unbekannt.</summary>
         public int VehicleOwner(string rootName)
         {
+            if (rootName == null) return SyncedBody.NoOwner;
             foreach (SyncedBody b in byId.Values)
                 if (b.IsVehicle && b.RootName == rootName) return b.OwnerId;
             return SyncedBody.NoOwner;