Replace pushd/popd directory stack usage with plain cd in ct/gramps-web.sh and install/gramps-web-install.sh, and remove the >/dev/null redirections. The frontend build and backend migration steps remain functionally the same but use simpler directory changes to avoid relying on pushd/popd output suppression.
Replace plain cd with pushd/popd (silenced) when building the frontend and running migrations to preserve the original working directory. Ensure database migrations run from /opt/gramps-web-api and export ALEMBIC_CONFIG in both install and update scripts so Alembic uses the correct config. Minor cleanup to silence directory stack output.
