Refactor SSH command in run-tests.sh to handle MUD connection closure gracefully

- Introduced a new function `ssh_mud` to encapsulate SSH command execution and treat exit code 255 as a success.
- Updated all SSH calls in the test script to use the new function for improved error handling.

run-tests.sh

@@ -4,6 +4,13 @@ set -e
 TEST_DB=${MUD_TEST_DB:-./mudserver.db.test}
 SERVER_PID=
 
+# SSH returns 255 when MUD closes connection after quit — treat as success
+ssh_mud() {
+  ssh -o StrictHostKeyChecking=no -o UserKnownHostsFile=/dev/null -p 2222 "$@"
+  r=$?
+  [[ $r -eq 0 || $r -eq 255 ]] || exit 1
+}
+
 cleanup() {
   if [ -n "${SERVER_PID:-}" ]; then
     kill $SERVER_PID 2>/dev/null || true
@@ -17,7 +24,7 @@ SERVER_PID=$!
 sleep 2
 
 # Test 1: New player creation + basic commands
-ssh -o StrictHostKeyChecking=no -o UserKnownHostsFile=/dev/null -p 2222 smoketest@localhost <<'EOF'
+ssh_mud smoketest@localhost <<'EOF'
 1
 1
 look
@@ -33,7 +40,7 @@ quit
 EOF
 
 # Test 2: Persistence - reconnect
-ssh -o StrictHostKeyChecking=no -o UserKnownHostsFile=/dev/null -p 2222 smoketest@localhost <<'EOF'
+ssh_mud smoketest@localhost <<'EOF'
 look
 stats
 quit
@@ -47,7 +54,7 @@ EOF
 ./target/debug/mudtool -d "$TEST_DB" settings list
 
 # Test 4: Admin commands in-game
-ssh -o StrictHostKeyChecking=no -o UserKnownHostsFile=/dev/null -p 2222 smoketest@localhost <<'EOF'
+ssh_mud smoketest@localhost <<'EOF'
 admin help
 admin list
 admin registration on
@@ -57,14 +64,14 @@ EOF
 
 # Test 5: Registration gate
 ./target/debug/mudtool -d "$TEST_DB" settings set registration_open false
-ssh -o StrictHostKeyChecking=no -o UserKnownHostsFile=/dev/null -p 2222 newplayer@localhost <<'EOF'
+ssh_mud newplayer@localhost <<'EOF'
 quit
 EOF
 
 # Test 6: Tick-based combat (connect and wait for ticks)
 ./target/debug/mudtool -d "$TEST_DB" settings set registration_open true
 ./target/debug/mudtool -d "$TEST_DB" players delete smoketest
-ssh -o StrictHostKeyChecking=no -o UserKnownHostsFile=/dev/null -p 2222 smoketest@localhost <<'EOF'
+ssh_mud smoketest@localhost <<'EOF'
 1
 1
 go south
@@ -72,7 +79,7 @@ go south
 attack thief
 EOF
 sleep 8
-ssh -o StrictHostKeyChecking=no -o UserKnownHostsFile=/dev/null -p 2222 smoketest@localhost <<'EOF'
+ssh_mud smoketest@localhost <<'EOF'
 stats
 quit
 EOF