Implement sync source-only mode in ServeSession and ChangeBatcher

- Added support for a new sync mode in ServeSession that filters property changes to only include the Source property when the server indicates it is in source-only mode.
- Updated ChangeBatcher to handle the new syncSourceOnly parameter, ensuring that only relevant property changes are processed based on the server's capabilities.
- Enhanced API response to include sync_source_only flag, indicating the server's sync capabilities.
- Adjusted related functions to accommodate the new sync logic, improving data synchronization efficiency.

plugin/src/ChangeBatcher/createPatchSet.lua

@@ -12,7 +12,7 @@ local PatchSet = require(script.Parent.Parent.PatchSet)
 
 local encodePatchUpdate = require(script.Parent.encodePatchUpdate)
 
-return function(instanceMap, propertyChanges)
+return function(instanceMap, propertyChanges, syncSourceOnly)
 	local patch = PatchSet.newEmpty()
 
 	for instance, properties in propertyChanges do
@@ -30,8 +30,20 @@ return function(instanceMap, propertyChanges)
 				Log.warn("Cannot sync non-nil Parent property changes yet")
 			end
 		else
-			local update = encodePatchUpdate(instance, instanceId, properties)
-			table.insert(patch.updated, update)
+			if syncSourceOnly then
+				-- Filter to only Source property when server is in source-only mode
+				if properties.Source then
+					local update = encodePatchUpdate(instance, instanceId, { Source = true })
+					if update then
+						table.insert(patch.updated, update)
+					end
+				end
+			else
+				local update = encodePatchUpdate(instance, instanceId, properties)
+				if update then
+					table.insert(patch.updated, update)
+				end
+			end
 		end
 
 		propertyChanges[instance] = nil

plugin/src/ChangeBatcher/init.lua

@@ -27,11 +27,16 @@ function ChangeBatcher.new(instanceMap, onChangesFlushed)
 		__instanceMap = instanceMap,
 		__onChangesFlushed = onChangesFlushed,
 		__pendingPropertyChanges = {},
+		__syncSourceOnly = false,
 	}, ChangeBatcher)
 
 	return self
 end
 
+function ChangeBatcher:setSyncSourceOnly(enabled)
+	self.__syncSourceOnly = enabled
+end
+
 function ChangeBatcher:stop()
 	self.__renderSteppedConnection:Disconnect()
 	self.__pendingPropertyChanges = {}
@@ -69,7 +74,7 @@ function ChangeBatcher:__flush()
 		return nil
 	end
 
-	local patch = createPatchSet(self.__instanceMap, self.__pendingPropertyChanges)
+	local patch = createPatchSet(self.__instanceMap, self.__pendingPropertyChanges, self.__syncSourceOnly)
 
 	if PatchSet.isEmpty(patch) then
 		return nil