fix d2oracle.set on imported edge

d2oracle/edit.go

@@ -476,14 +476,14 @@ func _set(g *d2graph.Graph, baseAST *d2ast.Map, key string, tag, value *string)
 			appendMapKey(scope, mk)
 			return nil
 		}
-		// TODO what if the edge is imported, how does this work?
 		var ok bool
 		edge, ok = obj.HasEdge(mk)
 		if !ok {
 			return errors.New("edge not found")
 		}
+		imported = IsImportedEdge(baseAST, edge)
 		refs := edge.References
-		if baseAST != g.AST {
+		if baseAST != g.AST || imported {
 			refs = getWriteableEdgeRefs(edge, baseAST)
 		}
 		onlyInChain := true

d2oracle/edit_test.go

@@ -2181,10 +2181,10 @@ layers: {
 			fsTexts: map[string]string{
 				"yo.d2": `a -> b`,
 			},
-			key:   `(a -> b).style.stroke`,
+			key:   `(a -> b)[0].style.stroke`,
 			value: go2.Pointer(`red`),
 			exp: `...@yo
-(a -> b).style.stroke: red
+(a -> b)[0].style.stroke: red
 `,
 		},
 	}