rename: failover → fallback throughout codebase — this system is Fallback, state is FALLBACK; preserve conventional failover comparisons

common.sh

@@ -48,7 +48,7 @@
 #            translate_path() added — container → host path for arr cleanup scripts
 #            check_arr_version() added — API version safety gate before arr operations
 #            check_api() added — pre-flight API reachability check
-#            ping_remote(), ping_internet() — non-fatal ping for failover use
+#            ping_remote(), ping_internet() — non-fatal ping for fallback use
 #            check_local_array(), check_remote_array() — array health checks
 #            check_remote_docker() — Docker daemon health check
 #            get_unraid_temp_thresholds() — reads thresholds from dynamix.cfg
@@ -159,7 +159,7 @@ ICON_LOCK="🔏"          # script instance lock — acquired/released
 ICON_RAM="💨"           # ramdisk operations — fast ephemeral storage
 ICON_LINK="🔗"          # symlink state and management
 
-# Failover Operations
+# fallback Operations
 ICON_FALLBACK="🔀"      # fallback state changes and operations
 
 # Docker Network Operations
@@ -656,7 +656,7 @@ resolve_tailscale_ip() {
 # ==============================================================================================
 
 # Fatal connectivity check — used by rsync and other scripts that must abort if unreachable.
-# For failover use ping_remote() which returns status without exiting.
+# For fallback use ping_remote() which returns status without exiting.
 check_connectivity() {
     log "Checking connectivity to $REMOTE_SERVER..."
     if ! ping -c1 -W3 "$REMOTE_SERVER" &>/dev/null; then
@@ -739,7 +739,7 @@ is_vm_manager_enabled() {
 
 # Verifies local /mnt/user is mounted and has shares.
 # Non-fatal — returns status for caller to decide.
-# Used by failover before starting remote containers locally.
+# Used by fallback before starting remote containers locally.
 check_local_array() {
     log "Checking local array..."
     if ! mountpoint -q /mnt/user 2>/dev/null; then
@@ -1660,7 +1660,7 @@ check_api() {
 # ==============================================================================================
 # Verifies local and remote servers are running compatible unRAID versions before any
 # remote operation. Version mismatches can mean changed APIs, commands, or behaviours
-# that silently break remote container operations, rsync, or failover logic.
+# that silently break remote container operations, rsync, or fallback logic.
 #
 # Reads /etc/unraid-version on both sides — format: version="7.2.3"
 #