Initial networking prototype is functional! Here's a work-in-progress video, with an explanation in the description below.
User coordinates printed to console via first Lua script ➡ VConsole2 runs with logging enabled (HL:A launch option -condebug) ➡ Java program scrapes coords from log, and writes a second Lua script containing these coords ➡ Second Lua script moves the red ball to coords.
The Java program sends those coordinates to itself over a network. This networking setup draws from a configuration file that designates server and client TCP/UDP ports, as well as client IP, client timeout (in ms), and HL:A log path.