MinecraftMcp

Server-lane heartbeat, standing in for the mod path's tickServer RETURN injection. Its own listener, so onEnable's registerEvents(this, this) doesn't register it early.

Hot-loaded into a running server (PlugMan et al) rather than booted with it — an UNSUPPORTED path, covered only because it is the one that breaks outright: onServerLoad is this host's sole opener of ReplBridge.pluginsLatch and starter of the heartbeat, and never fires there, hanging every eval rather than degrading one. Heuristic and best-effort, sound only while plugin.yml says load: STARTUP — that is what puts onEnable ahead of world loading. Wrong low is the old hang, now without a heartbeat as well; wrong high costs a script importing a plugin that attached its urls after this, and doubles the heartbeat once ServerLoadEvent fires too.

Plugin gate, standing in for the mod path's MixinDedicatedServer#initServer RETURN — fired right after enablePlugins(POSTWORLD), so every plugin's onEnable has returned and the urls it attached to its own loader are on it (see ReplBridge.pluginsLatch). MONITOR is the last priority BUCKET, not last outright: order within it is registration order, and nothing bounds a plugin that attaches later still.

The server has finished loading: onServerLoad, or the hot-load branch in onEnable — exclusive under load: STARTUP, so this runs once. Opens the plugin gate and starts the heartbeat.