Varaverk: arrange mode, folder management, rsync standalone, layout fixes

Scheduler UI:
- Arrange mode: drag scripts between orchs and reorder within arrays; right
  panel shows unassigned script pool; Save Arrangement commits to master.conf
- + Folder: named collapsible subfolders for Custom Scripts stored in schedule.json
- Rsync children: hide Run/Dry Run/Log/location when orch is ON; show standalone
  location + cron controls when orch is OFF; cron only fires when both filled
- Non-conf-managed children (transcode): toggles now show enabled when orch is on
- Right panel height sync: fix ResizeObserver feedback loop via align-self:flex-start
  on left panel and left.offsetHeight in vvFitRight
- How do I use this: updated to cover arrange, folders, rsync standalone, transcode

New API endpoints:
- board.php, clearlock.php, movescript.php, rawconf.php, readscript.php
- reorderarray.php, rsync_standalone.php, savefolders.php

run.php / dryrun.php: accept optional --location= arg for standalone rsync calls

Plugin/usr/local/emhttp/plugins/varaverk/Varaverk.page

@@ -9,7 +9,7 @@ $pluginDir = "$docroot/plugins/$plugin";
 
 // Determine active tab
 $tab = $_GET['tab'] ?? 'monitor';
-$validTabs = ['monitor', 'scheduler', 'config', 'docs'];
+$validTabs = ['monitor', 'scheduler'];
 if (!in_array($tab, $validTabs)) $tab = 'monitor';
 ?>