Fix vv_push_master_conf() — remote command was expanding locally, not on the remote host

The readiness probe wrapped the remote command in raw double quotes with
manually backslash-escaped inner quotes. shell_exec() runs its command
through an extra local `sh -c` layer beyond the ssh invocation itself, and
because the remote command was double-quoted (not single-quoted/opaque),
that extra local layer expanded the $(...)/${...} substitutions using
HOST1's own environment before ssh ever sent anything to the remote host.
Confirmed live: the exact same command run directly (one shell layer)
returned the correct remote SCRIPTS_DIR; run through an extra sh -c layer
(matching shell_exec's real behavior) it silently evaluated everything
against HOST1's local varaverk.cfg instead, producing an empty probe result
every time — so every push silently reported "plugin not installed" even
though HOST2 was fully installed and reachable.

Fix: build the remote command as a plain string and escapeshellarg() it as
a whole, same pattern vv_pt_ssh() already used safely elsewhere. Verified
live — probe now returns HOST2's real SCRIPTS_DIR and the master.conf push
lands with a matching checksum on both hosts.

Plugin/unraid/include/config.php

@@ -110,15 +110,18 @@ function vv_push_master_conf(): array {
         // Single SSH call: get remote SCRIPTS_DIR and verify plugin is installed,
         // Configurations/ exists, and master.conf is already present.
         // Any missing piece means the remote isn't ready — skip rather than push blind.
+        // Remote command built as one PHP string and escapeshellarg()'d whole — shell_exec()
+        // adds its own `sh -c` layer locally, so a bare double-quoted string here would let
+        // the $(...)/${...} substitutions expand on HOST1 before ssh ever sees them, instead
+        // of on the remote host. escapeshellarg() keeps it opaque until the remote shell runs it.
         $sshBase  = 'ssh -i ' . escapeshellarg($sshKey)
                   . ' -o ConnectTimeout=10 -o StrictHostKeyChecking=no root@' . $ip;
-        $probe    = trim(shell_exec(
-            $sshBase . ' "cfg=$(grep SCRIPTS_DIR /boot/config/plugins/varaverk/varaverk.cfg 2>/dev/null)'
-            . ' && sd=$(echo \"$cfg\" | grep -oP \'(?<=SCRIPTS_DIR=\")[^\"]+\')'
-            . ' && test -d \"${sd}/Configurations\"'
-            . ' && test -f \"${sd}/Configurations/master.conf\"'
-            . ' && echo \"$sd\""'
-        ) ?: '');
+        $remoteCmd = 'cfg=$(grep SCRIPTS_DIR /boot/config/plugins/varaverk/varaverk.cfg 2>/dev/null)'
+                   . ' && sd=$(echo "$cfg" | grep -oP \'(?<=SCRIPTS_DIR=")[^"]+\')'
+                   . ' && test -d "${sd}/Configurations"'
+                   . ' && test -f "${sd}/Configurations/master.conf"'
+                   . ' && echo "$sd"';
+        $probe    = trim(shell_exec($sshBase . ' ' . escapeshellarg($remoteCmd)) ?: '');
 
         if ($probe === '') {
             $results[] = ['host' => $hostKey, 'ok' => false, 'ready' => false,