@spec adjacency(connector_source()) :: %{optional(String.t()) => [String.t()]}

Returns a directed adjacency projection keyed by source item id.

Duplicate target ids are collapsed while preserving first-seen connector order.

@spec connector_draft_count(map() | term()) :: non_neg_integer()

Returns the number of active connector drafts in an assigned draft map.

@spec connectors_by_item(connector_source()) :: %{
  optional(String.t()) => [LivePanels.Item.t()]
}

Returns a map of item id to all connectors touching that item.

@spec connectors_by_port(connector_source()) :: %{
  optional({String.t(), String.t() | nil}) => [LivePanels.Item.t()]
}

Returns a map of {item_id, port_name} to connectors touching that port.

@spec connectors_for_item(connector_source(), String.t()) :: [LivePanels.Item.t()]

Returns all connectors touching item_id.

@spec connectors_for_port(connector_source(), String.t(), String.t() | atom()) :: [
  LivePanels.Item.t()
]

Returns all connectors touching port_name on item_id.

@spec creates_cycle?(connector_source(), String.t(), String.t()) :: boolean()

Returns true when adding a connector from from_id to to_id would create a cycle.

@spec incoming_connectors(connector_source(), String.t()) :: [LivePanels.Item.t()]

Returns connectors that target item_id.

@spec navigation(connector_source(), navigation_anchor(), direction(), keyword()) ::
  %{
    targets: [String.t()],
    selection: LivePanels.Canvas.Selection.t(),
    command: {:graph_select_elements, map()} | nil
  }

Returns ordered item ids reachable from a graph navigation anchor.

@spec outgoing_connectors(connector_source(), String.t()) :: [LivePanels.Item.t()]

Returns connectors that start from item_id.

@spec selected_connector?(LivePanels.Canvas.Selection.t(), String.t()) :: boolean()

Returns true when connector_id is selected in the given graph selection.

@spec selected_item?(LivePanels.Canvas.Selection.t(), String.t()) :: boolean()

Returns true when item_id is selected in the given graph selection.