fix: replace broken run.sh with direct Youer launch

- Remove premature --installServer call inside first-run block
  (Youer manages its own installation state via youer.yml)
- Remove chmod/run.sh which never existed (ATM10 5.4 ships startserver.sh)
- Replace ./run.sh with: java -jar youer.jar nogui
  This works for both first run (Youer self-installs) and subsequent runs

Fixes container always exiting immediately after first-run server stop.

launch.sh

@@ -29,7 +29,6 @@ if ! [[ -f "Server-Files-$SERVER_VERSION.zip" ]]; then
     fi
 
     curl -Lo neoforge-${NEOFORGE_VERSION}-installer.jar https://api.mohistmc.com/project/youer/1.21.1/builds/382/download
-    java -jar neoforge-${NEOFORGE_VERSION}-installer.jar --installServer
 fi
 
 if [[ -n "$JVM_OPTS" ]]; then
@@ -107,6 +106,5 @@ for raw_username in "${OPS[@]}"; do
 done
 
 sed -i 's/server-port.*/server-port=25565/g' server.properties
-chmod 755 run.sh
 
-./run.sh
+java -jar neoforge-${NEOFORGE_VERSION}-installer.jar nogui