This is intended! :)

At first, I tried to create a /web directory under src and add all the static resources there as we do with Azkaban core and other plugins. Then, I found that since the HDFS viewer plugin's URL scheme follows http://host/hdfs/path, then HDFS viewer will interpret /web *as a directory in HDFS*. I considered making an exception for /web, but then I thought that it shouldn't limit the names of the directories you could create in your HDFS.

As a result, I simply stored the JS and CSS in Velocity templates and inlined them.