Fix dead-variable and exit-code bugs found in codebase-wide audit

Same audit as the orchestrator standardization pass (2a062e5), extended to
every remaining script. Found the same class of bug independently recurring:
ramdisk_stop.sh checked $LOG (nothing assigns it, should be $ENABLE_LOGGING),
partnership_onboard.sh checked $LOG_MODE (same issue), emby_session_report.sh
checked $TRANSCODE_PCT which was never computed so the high-transcode alert
could never fire, and storage_migrate.sh never called detect_hosts() so
$MY_ID was empty, silently breaking the post-migration host*.conf update.
partnership_manager.sh used `local` at top-level script scope (invalid outside
a function) and had two master.conf path references missing "Configurations/".

Along the way: several scripts (share_setup.sh, conf_sync.sh,
downloaders_reset.sh, transcode_cleanup.sh, transcode_manager.sh,
remote_arr_cache_writer.sh, upgrade_webhook_handler.sh) had no explicit
trailing exit code, so they always reported success regardless of real
failures. play_state_sync.sh was missing the partnership gate its own header
documented, so remote play-state sync ran even with PARTNERSHIP_ENABLED=false;
it also always exited 0 on sync errors. arr_profile_enforcer.sh and
webhook_setup.sh hand-rolled their own flag parsing instead of common.sh's
parse_args, so --log silently did nothing on either.

system_watchdog.sh was itself an un-standardized mini-orchestrator — converted
to the shared run_orch_child()/JOB_PASS/JOB_FAIL pattern, added the missing
failure notification, and fixed dry-run to pass --dry-run down to children
instead of skipping them outright. Also fixed a stale webgui_watchdog.sh path
in master.conf.template that would break system_watchdog.sh on any fresh
install.

Closed a sibling-drift gap: radarr_cleanup.sh and sonarr_cleanup.sh were
missing lidarr_cleanup.sh's tracked-count percentage-drop safety gate and its
"not configured on this host, skip cleanly" guard — both now match Lidarr's
7-gate model.

Media/play_state_sync.sh

@@ -167,6 +167,12 @@ for _varname in $(compgen -v | grep -E '^HOST[0-9]+$' | sort); do
         continue
     fi
 
+    # Skip remote hosts when partnership is inactive
+    if [[ "$_is_me" == false && "${PARTNERSHIP_ENABLED:-false}" != "true" ]]; then
+        log "$_host_hostname — partnership inactive (PARTNERSHIP_ENABLED=false), skipping"
+        continue
+    fi
+
     # Resolve Tailscale IP for remote hosts
     _ts_ip=""
     if [[ "$_is_me" == false ]]; then
@@ -780,10 +786,15 @@ echo "$ICON_DONE  Synced:    $TOTAL_SYNCED"
 echo ""
 echo "  Favorites — synced: $FAV_TOTAL_SYNCED  skipped: $FAV_TOTAL_SKIPPED  errors: $FAV_TOTAL_ERRORS"
 
+TOTAL_ALL_ERRORS=$(( TOTAL_ERRORS + FAV_TOTAL_ERRORS ))
+
 if [[ "$DRY_RUN" == true ]]; then
     warn "DRY RUN — no changes written"
-elif [[ "$TOTAL_ERRORS" -eq 0 ]]; then
+    exit 0
+elif [[ "$TOTAL_ALL_ERRORS" -eq 0 ]]; then
     success "Done ✅"
+    exit 0
 else
-    warn "Done with $TOTAL_ERRORS error(s)"
+    warn "Done with $TOTAL_ALL_ERRORS error(s)"
+    exit 1
 fi