fix: cd to site dir before docker compose commands

docker compose stats the cwd when parsing compose files; if cwd is
not accessible to the deploy user the command fails.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

deploy/deploy.sh

@@ -6,6 +6,8 @@ set -euo pipefail
 SITE_DIR=/srv/sum/nohype
 APP_DIR=${SITE_DIR}/app
 
+cd "${SITE_DIR}"
+
 echo "==> Pulling latest code"
 git -C "${APP_DIR}" pull origin main