NightbreakDevUpdateSource

Swaps new local builds into a running test server. Off unless the server JVM sets -Dnightbreak.devUpdateSource=<folder>; the testbed start scripts point it at the workspace dist/ folder, where every build mirrors its jar.

Each plugin watches the file in that folder named like its own jar. A finished build whose bytes differ from the running jar is staged in the update folder and swapped in at once through NightbreakPluginHotSwap, even when it keeps the same version. A build that is refused or fails to enable is not tried again; the next build is.

The watcher polls on its own thread rather than as a scheduler task, because reload commands cancel every scheduler task of their plugin, and some of them never run the update bootstrap again. It stops when MagmaCore shuts the plugin down or the plugin is disabled.