Update syncback feature to handle instance pulling from Studio

- Updated the `ServeSession` to implement logic for pulling instances that exist in Studio but not in Rojo's filesystem, creating appropriate files during sync confirmation.
- Introduced a new `encodeInstance` function to serialize Studio instances for transmission, supporting all instance types.
- Modified the `PatchTree` to allow explicit user selection for push/pull/skip actions, enhancing user control during sync operations.
- Added tests for the new encoding functionality and updated existing tests to ensure proper behavior with the new syncback logic.

plugin/src/ChangeBatcher/encodeInstance.lua

@@ -0,0 +1,132 @@
+--[[
+	Encodes a Roblox Studio instance into a format suitable for transmission
+	to the Rojo server for syncback (creating files from Studio instances).
+	
+	Supports ALL instance types:
+	- Scripts (ModuleScript, Script, LocalScript) -> .luau files or directories with init files if has children
+	- Folders -> directories (with Attributes if present)
+	- All other instances -> .model.json files or directories
+	
+	Children are recursively encoded and included.
+]]
+
+local Packages = script.Parent.Parent.Parent.Packages
+local Log = require(Packages.Log)
+local RbxDom = require(Packages.RbxDom)
+
+local encodeProperty = require(script.Parent.encodeProperty)
+
+-- Script class names that need Source property
+local SCRIPT_CLASS_NAMES = {
+	Script = true,
+	LocalScript = true,
+	ModuleScript = true,
+}
+
+-- Properties to skip when encoding (internal Roblox properties)
+local SKIP_PROPERTIES = {
+	Parent = true,
+	Name = true, -- We handle this separately
+	Archivable = true,
+}
+
+-- Classes that become directories but may have properties (like Attributes)
+local DIRECTORY_CLASSES = {
+	Folder = true,
+	Configuration = true,
+	Tool = true,
+	ScreenGui = true,
+	SurfaceGui = true,
+	BillboardGui = true,
+	AdGui = true,
+}
+
+-- Forward declaration for recursion
+local encodeInstance
+
+-- Encode Attributes if present on any instance
+local function encodeAttributes(instance, properties)
+	-- Try to get Attributes - this works for all instance types
+	local success, attributes = pcall(function()
+		return instance:GetAttributes()
+	end)
+
+	if success and attributes and next(attributes) then
+		-- Attributes need to be encoded specially
+		-- The server expects them in the properties map under "Attributes"
+		local attributeDescriptor = RbxDom.findCanonicalPropertyDescriptor(instance.ClassName, "Attributes")
+		if attributeDescriptor then
+			local encodeSuccess, encodeResult = encodeProperty(instance, "Attributes", attributeDescriptor)
+			if encodeSuccess and encodeResult ~= nil then
+				properties.Attributes = encodeResult
+			end
+		end
+	end
+end
+
+encodeInstance = function(instance, parentId)
+	local properties = {}
+
+	-- Always try to encode Attributes for any instance type
+	encodeAttributes(instance, properties)
+
+	if SCRIPT_CLASS_NAMES[instance.ClassName] then
+		-- For scripts, encode the Source property
+		local sourceDescriptor = RbxDom.findCanonicalPropertyDescriptor(instance.ClassName, "Source")
+		if sourceDescriptor then
+			local encodeSuccess, encodeResult = encodeProperty(instance, "Source", sourceDescriptor)
+			if encodeSuccess then
+				properties.Source = encodeResult
+			else
+				Log.warn("Failed to encode Source property for {:?}", instance)
+				return nil
+			end
+		else
+			Log.warn("Could not find Source property descriptor for {:?}", instance)
+			return nil
+		end
+	elseif not DIRECTORY_CLASSES[instance.ClassName] then
+		-- For non-directory, non-script classes, encode all relevant properties
+		local classDescriptor = RbxDom.findClassDescriptor(instance.ClassName)
+		if classDescriptor then
+			for propertyName, propertyDescriptor in classDescriptor.properties do
+				if SKIP_PROPERTIES[propertyName] then
+					continue
+				end
+
+				-- Skip Attributes here since we handle it separately above
+				if propertyName == "Attributes" then
+					continue
+				end
+
+				-- Only encode serializable properties
+				if propertyDescriptor.scriptability == "ReadWrite" or propertyDescriptor.scriptability == "Read" then
+					local encodeSuccess, encodeResult = encodeProperty(instance, propertyName, propertyDescriptor)
+					if encodeSuccess and encodeResult ~= nil then
+						properties[propertyName] = encodeResult
+					end
+				end
+			end
+		end
+	end
+	-- For directory classes (Folder, Configuration, etc.), we only encode Attributes (done above)
+
+	-- Recursively encode children
+	local children = {}
+	for _, child in ipairs(instance:GetChildren()) do
+		local encodedChild = encodeInstance(child, nil) -- parentId will be resolved server-side
+		if encodedChild then
+			table.insert(children, encodedChild)
+		end
+	end
+
+	return {
+		parent = parentId,
+		name = instance.Name,
+		className = instance.ClassName,
+		properties = properties,
+		children = children, -- Include children array (may be empty)
+	}
+end
+
+return encodeInstance