Connect pseudofield sources to use in pipeline

Pseudofield edges are working now, but the chart isn't yet to my liking.

The following module-generated Mermaid works on mermaid.live, but doesn't in the module's render of the same output. I'm having trouble activating the Elk layout renderer.

---
# Generated with Migrate Visualize
# https://drupal.org/project/migrate_visualize
---
flowchart LR

subgraph Source[fa:fa-cloud-download Source]
  source:meta:plugin["plugin: url"]
  source:field:id["id"]
  source:field:title["title"]
  source:field:link["link"]
  source:field:updated["updated"]
  source:field:data["data"]
  source:field:content["content"]
  source:field:constants_subtype["constants/subtype"]
  source:field:__path_parts_3["@_path_parts/3"]
  source:field:__path_parts_4["@_path_parts/4"]
  source:field:__term_names["@_term_names"]
end

subgraph Destination[fa:fa-cloud-upload Destination]
  destination:meta:plugin["plugin: entity:node"]
  destination:field:created["created"]
  destination:field:changed["changed"]
  destination:field:title["title"]
  destination:field:type["type"]
  destination:field:field_remote_id["field_remote_id"]
  destination:field:field_data["field_data"]
  destination:field:field_subtype["field_subtype"]
  destination:field:_path_parts["_path_parts"]
  destination:field:_term_names["_term_names"]
  destination:field:field_tags["field_tags"]
  destination:field:field_url["field_url"]
end

subgraph Process[fa:fa-cloud-upload Process]
  process:field:created["created"]
  process:field:created:1["format_date"]
  process:field:changed["changed"]
  process:field:changed:1["format_date"]
  process:field:title["title"]
  process:field:title:0["get"]
  process:field:type["type"]
  process:field:type:0["default_value"]
  process:field:field_remote_id["field_remote_id"]
  process:field:field_remote_id:0["get"]
  process:field:field_data["field_data"]
  process:field:field_data:1["callback: json_encode"]
  process:field:field_subtype["field_subtype"]
  process:field:field_subtype:1["entity_generate"]
  process:field:_path_parts["_path_parts"]
  process:field:_path_parts:1["skip_on_empty"]
  process:field:_path_parts:2["explode"]
  process:field:_term_names["_term_names"]
  process:field:_term_names:0["get"]
  process:field:_term_names:1["callback: array_filter"]
  process:field:_term_names:2["callback: array_unique"]
  process:field:field_tags["field_tags"]
  process:field:field_tags:1["entity_generate"]
  process:field:field_url["field_url"]
  process:field:field_url:0["get"]
end

source:field:updated --> process:field:created:1
process:field:created:1 --> process:field:created
process:field:created --> destination:field:created
source:field:updated --> process:field:changed:1
process:field:changed:1 --> process:field:changed
process:field:changed --> destination:field:changed
source:field:title --> process:field:title:0
process:field:title:0 --> process:field:title
process:field:title --> destination:field:title
process:field:type:0 --> process:field:type
process:field:type --> destination:field:type
source:field:id --> process:field:field_remote_id:0
process:field:field_remote_id:0 --> process:field:field_remote_id
process:field:field_remote_id --> destination:field:field_remote_id
source:field:data --> process:field:field_data:1
process:field:field_data:1 --> process:field:field_data
process:field:field_data --> destination:field:field_data
source:field:constants_subtype --> process:field:field_subtype:1
process:field:field_subtype:1 --> process:field:field_subtype
process:field:field_subtype --> destination:field:field_subtype
source:field:link --> process:field:_path_parts:1
process:field:_path_parts:1 --> process:field:_path_parts:2
process:field:_path_parts:2 --> process:field:_path_parts
process:field:_path_parts --> destination:field:_path_parts
source:field:__path_parts_3 --> process:field:_term_names:0
source:field:__path_parts_4 --> process:field:_term_names:0
process:field:_term_names:0 --> process:field:_term_names:1
process:field:_term_names:1 --> process:field:_term_names:2
process:field:_term_names:2 --> process:field:_term_names
process:field:_term_names --> destination:field:_term_names
source:field:__term_names --> process:field:field_tags:1
process:field:field_tags:1 --> process:field:field_tags
process:field:field_tags --> destination:field:field_tags
source:field:link --> process:field:field_url:0
process:field:field_url:0 --> process:field:field_url
process:field:field_url --> destination:field:field_url

destination:field:_term_names --> source:field:__term_names

Mermaid.live rendering with Elk:

Migrate Visualize rendering without Elk:

Looks like I've broken the "copy source" JS with WIP also.