Add one-command server mod updates: build_mods.py --push via update.sh (stop/sync/start, prunes stale jars)

README.md

@@ -35,6 +35,21 @@ cd ~/reaper-sky-server && ./run.sh
 The world generates on first boot — wait for `Done (...)` and join at
 `reaperofveriod.nl`. Full details in [`server/README.md`](server/README.md).
 
+## Updating the server's mods (maintainers)
+
+After adding/removing mods in the Prism instance `Reaper's Sky - dev`, push
+them to the live server with one command from the repo root:
+
+```sh
+python3 server/build_mods.py --push
+```
+
+It regenerates `server/mods.json`, uploads it, then on the server:
+**stop → sync mods (prune stale + download new, sha1-verified) → start**, and
+waits until the log shows `Done (...)`. No git commit needed first. See
+[`server/README.md`](server/README.md#updating-the-servers-mods) for details,
+manual options and troubleshooting.
+
 ## What's inside
 
 <details open>