Replace the old curl-based installer and interactive update menu with unified GitHub release deployment helpers. ct/surrealdb.sh now checks for a new surrealdb release via check_for_gh_release, stops the service, uses fetch_and_deploy_gh_release to deploy the prebuilt binary to /usr/local/bin, sets exec permissions, and restarts the service (also use ${APP} in an error message). The previous menu-driven update and storage-switch options (memory vs rocksdb) were removed. install/surrealdb-install.sh now skips the removed mc dependency install, uses fetch_and_deploy_gh_release instead of the install.surrealdb.com script, makes the binary executable, and no longer writes a release-version file. Overall moves to a consistent release fetch/deploy flow and simplifies update/install logic.
