Adds require_partnership() to common.sh — exits cleanly when PARTNERSHIP_ENABLED=false.
Removes FALLBACK_PARTNERSHIP_REQUIRED toggle — partnership is now always required,
not optional. Cross-server scripts (rsync, conf sync, fallback, arr sync, play state,
backup verify) all call require_partnership after detect_hosts.
conf_cache_save.sh runs first on array stop — snapshots partner confs from RAM
cache to /boot/config/varaverk/conf_bak/ before anything else shuts down.
conf_cache_restore.sh runs after conf_sync.sh on array start — if partner was
unreachable and RAM cache is incomplete, loads the backup into RAM then removes
it. Normal reboots: backup written, fresh pull succeeds, backup deleted unused.
Edge case (partner down at boot): backup fills the gap so fallback.sh has the
partner vars it needs to operate correctly.
Gmer4Lfe