Add Varaverk plugin scaffold (PHP, unRAID native)

Plugin lives in Plugin/ — invisible to User Script Plugin.
dev_install.sh symlinks into /usr/local/emhttp/plugins/varaverk/ for development.

Pages: Monitor (5s poll), Scheduler (orchs + Advanced children, toggle + cron),
Config (raw editor, host-aware file access), Docs (markdown + live $VAR substitution).

API endpoints: monitor.php (JSON), scheduler.php (writes schedule.json + cron.d),
config.php (writes conf files with host permission check).

Includes: config.php (parser, host detection, var map), scheduler.php (job tree,
cron.d rebuild), monitor.php (docker, GPU, resources, fallback, transcode),
docs.php (file tree, var substitution, Parsedown renderer).

Plugin/usr/local/emhttp/plugins/varaverk/pages/docs.php

@@ -0,0 +1,44 @@
+<?php
+require_once dirname(__DIR__) . '/include/docs.php';
+require_once dirname(__DIR__) . '/include/config.php';
+
+$tree    = vv_docs_tree();
+$vars    = vv_conf_vars();
+$active  = $_GET['doc'] ?? '';
+
+// Validate: must be a .md file within SCRIPTS_DIR
+$active = preg_match('/^[a-zA-Z0-9_\-\/]+\.md$/', $active) ? $active : '';
+if ($active && !file_exists(SCRIPTS_DIR . '/' . $active)) $active = '';
+?>
+
+<div id="vv-docs">
+
+  <div id="vv-docs-sidebar">
+    <h3>Documents</h3>
+    <ul>
+      <?php foreach ($tree as $rel): ?>
+        <li>
+          <a href="?tab=docs&doc=<?= urlencode($rel) ?>"
+             class="<?= $rel === $active ? 'active' : '' ?>">
+            <?= htmlspecialchars($rel) ?>
+          </a>
+        </li>
+      <?php endforeach; ?>
+    </ul>
+  </div>
+
+  <div id="vv-docs-content">
+    <?php if ($active): ?>
+      <div class="vv-doc-body">
+        <?= vv_docs_render($active, $vars) ?>
+      </div>
+      <p class="vv-doc-hint">
+        Values shown in <code class="vv-live-var">green</code> are live from your conf files.
+        <code class="vv-unknown-var">Orange</code> means the variable was not found.
+      </p>
+    <?php else: ?>
+      <p>Select a document from the sidebar.</p>
+    <?php endif; ?>
+  </div>
+
+</div>