fixup! Add Valkey and PostgreSQL (closes #9)

Model: deepseek-v4-pro

build.sh

@@ -168,7 +168,7 @@ bundle --version
 valkey-server --version
 valkey-cli --version
 valkey-server /etc/valkey/valkey.conf
-valkey-cli ping
+ok=; for i in $(seq 1 50); do if valkey-cli ping 2>/dev/null | grep -q PONG; then ok=1; break; fi; sleep 0.1; done; [ -n "$ok" ]
 valkey-cli shutdown nosave
 psql --version
 postgres --version
@@ -190,6 +190,8 @@ virtualenv --version
 test -x /usr/local/sbin/runsvinit
 test -d /etc/service
 
-# The checks above leave caches behind (node compile cache etc).
+# The checks above leave caches and log files behind.
 rm -rf /tmp/* /var/tmp/* /root/.cache /root/.npm /root/.config
+rm -f /var/log/valkey/*
+install -d -o valkey -g adm -m 2750 /var/log/valkey
 rm -f "$0"