Bundles four reference script overlays (cedapug_maps, l4d2center_maps,
competitive_rework, tickrate) and adds a `flask seed-script-overlays`
CLI that upserts each *.sh as a system-wide overlay. Test deploy
invokes it after the orphan-cleanup migration so fresh test servers
come up with the same overlays the user has been maintaining by hand.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>