Fix PUID/PGID collision issues by using gosu to run services with exact UID:GID. Changes include:
- Added redis-start.sh and updated app-start.sh to load /etc/environment, determine PUID/PGID, and invoke gosu "$PUID:$PGID" to start Redis and the Next.js app (with verification and fallbacks).
- Updated entrypoint.sh to persist PUID/PGID into /etc/environment, document the gosu approach, and adjust startup messaging.
- Updated supervisord.conf to run the new startup wrappers as root (so they can use gosu) instead of running processes directly as specific users.
- Dockerfile updated to install gosu and copy the redis-start.sh wrapper.
- Documentation updated (deployment/unified.md) describing the PUID collision bug, the root cause, and the gosu-based fix.
This resolves cases where PUID collides with existing system users (e.g., nobody) which previously caused processes to run with the wrong GID and produce EACCES errors.
Re-declared build arguments GIT_COMMIT and BUILD_DATE after the FROM instruction to ensure they are available in subsequent build stages, as ARGs before FROM are not accessible after the base image is set.
Implements optional filesystem scan triggering for Plex and Audiobookshelf after file organization, with new settings in the admin UI, setup wizard, and API. Updates documentation to reflect scan trigger options and improved file organization/cleanup logic. Refactors dropdown menus to use smart positioning and portals for better UX. Adds a version API route and a VersionBadge component to display build info in the header. Updates Docker build to inject version metadata.