Well, I ended up figuring out the solution…
[mpixel@server NodeApp]$ ls -la
total 140
drwxr-xr-x. 11 mpixel mpixel 4096 Aug 8 18:58 .
drwxr-xr-x. 6 mpixel mpixel 181 Aug 1 13:28 ..
srwxr-xr-x. 1 root root 0 Aug 8 12:50 0.0.0.0:443
srwxr-xr-x. 1 root root 0 Aug 8 12:50 0.0.0.0:80
srwxr-xr-x. 1 mpixel mpixel 0 Aug 8 14:05 0.0.0.0:8000
srwxr-xr-x. 1 mpixel mpixel 0 Aug 8 14:23 0.0.0.0:8001
srwxr-xr-x. 1 mpixel mpixel 0 Aug 8 14:38 0.0.0.0:8002
srwxr-xr-x. 1 mpixel mpixel 0 Aug 8 14:05 0.0.0.0:8443
srwxr-xr-x. 1 mpixel mpixel 0 Aug 8 14:23 0.0.0.0:8444
srwxr-xr-x. 1 mpixel mpixel 0 Aug 8 14:38 0.0.0.0:8445
srwxr-xr-x. 1 mpixel mpixel 0 Aug 8 14:56 0.0.0.0:9000
srwxr-xr-x. 1 mpixel mpixel 0 Aug 8 14:56 0.0.0.0:9001
srwxr-xr-x. 1 mpixel mpixel 0 Aug 8 15:42 0.0.0.0:9002
srwxr-xr-x. 1 mpixel mpixel 0 Aug 8 15:42 0.0.0.0:9003
srwxr-xr-x. 1 mpixel mpixel 0 Aug 8 16:05 192.168.23.77:8000
srwxr-xr-x. 1 mpixel mpixel 0 Aug 8 16:05 192.168.23.77:8443
srwxr-xr-x. 1 mpixel mpixel 0 Aug 8 16:46 '*:443'
srwxr-xr-x. 1 mpixel mpixel 0 Aug 8 16:46 '*:80'
...
Evidently, when given “0.0.0.0:####” as a port, Express / NodeJS will create a Unix socket on the filesystem, relative to the current working directory, and doesn’t clean it up. These can be simply removed with rm.