Fix dead/incorrect vars and consolidate duplicated logic into common.sh

Codebase-wide audit pass: fixed real bugs (SSH hangs missing BatchMode,
local-outside-function no-ops, variable name collisions, a truncated
ratio calc, wrong state-dir path, DARK vs NO_INTERNET drift, and more),
then pulled logic that was duplicated across multiple scripts — arr
cleanup safety gates, docker restart ordering, container maintenance
stop/restart, watchdog state-file helpers, partnership role resolution,
cert expiry checks, remote node discovery, and TMDB discovery scoring —
into common.sh so each now has a single implementation.

Partnership/partnership_onboard.sh

@@ -223,20 +223,7 @@ fi
 
 detect_hosts
 
-OWNER_ID="${PARTNERSHIP_OWNER_HOST:-HOST1}"
-MIRROR_ID=$( [[ "$OWNER_ID" == "HOST1" ]] && echo "HOST2" || echo "HOST1" )
-OWNER="${!OWNER_ID}"
-MIRROR="${!MIRROR_ID}"
-# SSH_KEY (set by detect_hosts) is this server's own private key.
-# The remote accepts it because this server's PUBLIC key was installed there via ssh_setup.sh.
-# HOST{N}_SSH_KEY lives in host{N}.conf — with sparse checkout, the other server's
-# conf is never present here. Always use SSH_KEY (local private key) for outbound SSH.
-MIRROR_SSH_KEY="$SSH_KEY"
-
-AM_OWNER=false
-AM_MIRROR=false
-[[ "$MY_ID" == "$OWNER_ID" ]] && AM_OWNER=true
-[[ "$MY_ID" == "$MIRROR_ID" ]] && AM_MIRROR=true
+partnership_resolve_roles
 
 EXTRA_FLAGS=()
 [[ "$DRY_RUN"  == true ]] && EXTRA_FLAGS+=("--dry-run")
@@ -250,11 +237,7 @@ write_onboard_phase() {
     local key="${target_id}_PHASE${phase}_DONE"
     local state_file="$(platform_setup_db_path)"
     [[ "$DRY_RUN" == true ]] && { warn "DRY RUN — would write ${key}=true"; return 0; }
-    if grep -q "^${key}=" "$state_file" 2>/dev/null; then
-        sed -i "s|^${key}=.*|${key}=true|" "$state_file"
-    else
-        echo "${key}=true" >> "$state_file"
-    fi
+    set_state_var "$state_file" "$key" "true"
     platform_push_setup_state
 }
 
@@ -282,13 +265,7 @@ stop_mirror_stack() {
     local config_var="$1" label="$2"
     local -a to_stop=()
 
-    mapfile -t to_stop < <(
-        timeout "$SSH_TIMEOUT" ssh -i "$MIRROR_SSH_KEY" \
-            -o ConnectTimeout="$SSH_TIMEOUT" -o BatchMode=yes root@"$MIRROR_IP" \
-            "source '$SCRIPTS_ROOT/load_config.sh' 2>/dev/null
-             detect_hosts 2>/dev/null
-             printf '%s\n' \"\${${config_var}[@]:-}\"" 2>/dev/null | grep -v '^$'
-    )
+    mapfile -t to_stop < <(read_remote_conf_array "$MIRROR_IP" "$config_var" | grep -v '^$')
 
     if [[ ${#to_stop[@]} -eq 0 ]]; then
         log "No $label containers to stop on $MIRROR — skipping"
@@ -302,7 +279,7 @@ stop_mirror_stack() {
             continue
         fi
         timeout "$SSH_TIMEOUT" ssh -i "$MIRROR_SSH_KEY" \
-            -o ConnectTimeout="$SSH_TIMEOUT" root@"$MIRROR_IP" \
+            -o ConnectTimeout="$SSH_TIMEOUT" -o BatchMode=yes root@"$MIRROR_IP" \
             "docker stop '$container' 2>/dev/null
              docker rm   '$container' 2>/dev/null && echo removed" 2>/dev/null | \
             grep -q removed && \
@@ -338,11 +315,7 @@ if [[ "$AM_MIRROR" == true ]]; then
 
     if [[ -n "$OWNER_IP" ]]; then
         # Read OWNER's SCRIPTS_DIR via platform probe command — don't assume same path as mirror
-        _probe_cmd=$(platform_scripts_dir_probe_cmd)
-        OWNER_SCRIPTS_DIR=$(timeout "$SSH_TIMEOUT" ssh -i "$SSH_KEY" \
-            -o ConnectTimeout="$SSH_TIMEOUT" -o BatchMode=yes root@"$OWNER_IP" \
-            "$_probe_cmd" 2>/dev/null | tr -d '[:space:]')
-        OWNER_SCRIPTS_DIR="${OWNER_SCRIPTS_DIR:-$SCRIPTS_DIR}"
+        OWNER_SCRIPTS_DIR=$(resolve_remote_scripts_dir "$OWNER_IP")
 
         if [[ "$DRY_RUN" == true ]]; then
             warn "DRY RUN — would SSH to $OWNER ($OWNER_IP) and trigger Phase 2"
@@ -444,11 +417,9 @@ elif [[ "$PHASE1_ONLY" == true ]]; then
                 echo "  Then click 'Push Conf' in the Partnership tab."
                 # Write key-ready flag so UI can show the manual-install state
                 [[ "$DRY_RUN" == false ]] && {
-                    local kflag="${MIRROR_ID}_KEY_READY"
-                    local _setup_f="$(platform_setup_db_path)"
-                    grep -q "^${kflag}=" "$_setup_f" 2>/dev/null \
-                        && sed -i "s|^${kflag}=.*|${kflag}=true|" "$_setup_f" \
-                        || echo "${kflag}=true" >> "$_setup_f"
+                    kflag="${MIRROR_ID}_KEY_READY"
+                    _setup_f="$(platform_setup_db_path)"
+                    set_state_var "$_setup_f" "$kflag" "true"
                 }
             fi
             STEP_SSH_OK=false