encode OcaRoot references as object numbers in dataset serialization

OcaRoot.encode(to:) now always encodes just the objectNumber, for all
encoder types. Deep serialization of object state is already handled by
OcaBlock.serialize() which calls serialize() on each action object
directly. This means any @OcaDeviceProperty that holds OcaRoot
references (e.g. OcaGroup.members) will automatically serialize as
OcaONos rather than attempting to encode full object state.

On the deserialization side, OcaDeviceProperty.set(object:jsonValue:)
now resolves [OcaONo] and OcaONo values back to objects via the device
object registry.

Note: deserialization assumes that the referenced objects have already
been instantiated (i.e. the containing block's action objects are
deserialized before any property referencing them). This ordering is
currently guaranteed by the block deserialization traversal but may
need explicit handling if that assumption changes.

Author: lhoward

Sources/SwiftOCADevice/OCC/ControlClasses/Root.swift

@@ -142,36 +142,15 @@ open class OcaRoot: CustomStringConvertible, Codable, Sendable, _OcaObjectKeyPat
   }
 
   public nonisolated func encode(to encoder: Encoder) throws {
-    if encoder._isOcp1Encoder {
-      var container = encoder.unkeyedContainer()
-      try container.encode(objectNumber)
-    } else {
-      var container = encoder.container(keyedBy: CodingKeys.self)
-      try container.encode(Self.classID.description, forKey: .classIdentification)
-      try container.encode(objectNumber, forKey: .objectNumber)
-      try container.encode(lockable, forKey: .lockable)
-      try container.encode(role, forKey: .role)
-    }
+    // Always encode as just the object number. Deep serialization of object
+    // state is handled by OcaBlock.serialize() which calls serialize() on
+    // each action object directly, not through Codable.
+    var container = encoder.unkeyedContainer()
+    try container.encode(objectNumber)
   }
 
   public required nonisolated init(from decoder: Decoder) throws {
-    if decoder._isOcp1Decoder {
-      throw Ocp1Error.notImplemented
-    } else {
-      let container = try decoder.container(keyedBy: CodingKeys.self)
-      let classID = try OcaClassID(
-        container
-          .decode(String.self, forKey: .classIdentification)
-      )
-      guard classID == Self.classID else {
-        throw Ocp1Error.objectClassMismatch
-      }
-
-      objectNumber = try container.decode(OcaONo.self, forKey: .objectNumber)
-      lockable = try container.decode(OcaBoolean.self, forKey: .lockable)
-      role = try container.decode(OcaString.self, forKey: .role)
-      Task { @OcaDevice in deviceDelegate = OcaDevice.shared }
-    }
+    throw Ocp1Error.notImplemented
   }
 
   public nonisolated var description: String {

Sources/SwiftOCADevice/OCC/PropertyTypes/DeviceProperty.swift

@@ -191,6 +191,24 @@ public struct OcaDeviceProperty<Value: Codable & Sendable>: OcaDevicePropertyRep
         throw Ocp1Error.status(.badFormat)
       }
       await setAndNotifySubscribers(object: object, objects)
+    } else if let objectNumbers = jsonValue as? [OcaONo] {
+      // resolve an array of object numbers to objects
+      var objects = [OcaRoot]()
+      for oNo in objectNumbers {
+        if let resolved = await device.objects[oNo] {
+          objects.append(resolved)
+        }
+      }
+      guard let objects = objects as? Value else {
+        throw Ocp1Error.status(.badFormat)
+      }
+      await setAndNotifySubscribers(object: object, objects)
+    } else if let objectNumber = jsonValue as? OcaONo {
+      // resolve a single object number to an object
+      guard let resolved = await device.objects[objectNumber] as? Value else {
+        throw Ocp1Error.status(.badFormat)
+      }
+      await setAndNotifySubscribers(object: object, resolved)
     } else {
       if JSONSerialization.isValidJSONObject(subject.value) {
         // Value is a JSON-native type (e.g. dictionary, array) — direct cast