Minimal PocketBase bootstrap for the v2 stack (backend + runner + ui-v2).
Creates only the 6 collections actually used by v2:
books, chapters_idx, ranking, progress, scraping_tasks, audio_jobs
Drops v1-only collections (app_users, user_settings, audio_cache,
book_comments, comment_votes, user_library, user_sessions,
user_subscriptions) and unused fields (date_label, user_id/audio_time
on progress). heartbeat_at is included in create_collection from the
start and also covered by ensure_field for existing instances.
docker-compose-new.yml pb-init service now mounts pb-init-v2.sh.
