How to combine lists on the command line (jq)?

I have two files with JSON lists:

File 1

[0,1,2]["a", "b", "c"]

File 2

[3,4,5]["d", "e", "f"]

How can I use jq or a similar command line tool to combine the lists in each line? The result from combining the two files above should be :

[0,1,2,3,4,5]["a", "b", "c", "d", "e", "f"]