feat(core): Change workflow deletions to soft deletes (#14894)

Adds soft‑deletion support for workflows through a new boolean column `isArchived`.

When a workflow is archived we now set `isArchived` flag to true and the workflows
stays in the database and is omitted from the default workflow listing query.

Archived workflows can be viewed in read-only mode, but they cannot be activated.

Archived workflows are still available by ID and can be invoked as sub-executions,
so existing Execute Workflow nodes continue to work. Execution engine doesn't
care about isArchived flag.

Users can restore workflows via Unarchive action at the UI.

packages/frontend/editor-ui/src/components/Folders/FolderCard.test.ts

@@ -31,7 +31,6 @@ const DEFAULT_FOLDER: FolderResource = {
 	createdAt: new Date().toISOString(),
 	updatedAt: new Date().toISOString(),
 	resourceType: 'folder',
-	readOnly: false,
 	workflowCount: 2,
 	subFolderCount: 2,
 	homeProject: {