fix(dev): reduce introspection timeouts + spawn/kill process _groups_

[EverlastingBugstopper]

this PR fixes #1219 and #1230

• when spawning processes, spawn them into a process group instead of just a process. now, when we kill processes, it actually... kills the processes. before, if npm run start spawns nodemon and nodemon spawns node index.js, only the npm process would be killed. now they are all killed.
• set the introspection timeout to 2 seconds instead of 30 seconds when scanning your local network.