MSU

Server upgrades no longer mark a mod incompatible when a mod is republished with the same version number for the target Minecraft version (for example 0.6.6 for 26.2 vs 0.6.6 for 26.3).

/msu stage self keeps the live updater jar until wrapper apply. Staging a newer filename used to delete every MSU jar in mods/ first, so apply quarantined the plan (Staged plan expected to replace a file, but it is missing) and start.sh could not find an updater jar. Obsolete-jar cleanup also refuses to wipe mods/ when the keep file is not on disk.