feat: add videodb media index with Docker stack

- Add videodb PHP/MySQL media collection manager (Blu-ray, DVD, CD)
- Dockerfile: PHP 8.1 + Apache with GD/mysqli/exif extensions
- docker-compose.yml: app on port 6761 + MySQL 8.0 with health checks
- docker-entrypoint.sh: auto-generates config.inc.php from env vars,
  waits for MySQL, initializes DB schema idempotently
- init-db.php: CLI schema installer using app's own prefix_query() logic
- Persistent volumes for DB, cache, and cover images

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

videodb/templates/modern/trace.tpl

@@ -0,0 +1,25 @@
+{*
+  Template for IMDB Online browsing
+  $Id: trace.tpl,v 2.11 2005/10/13 19:30:55 andig2 Exp $
+*}
+
+<table width="100%" cellspacing="0" cellpadding="0">
+<tr><td>
+    <table width="100%" class="tablefilter" cellspacing="5">
+    <tr><td width="100%">
+        <span class="filterlink">URL: </span><a href="{$url}" target="_blank">{$url}</a>
+    </td>
+    <td align="right">
+        <nobr>{if $fetchtime}<span class="filterlink">{$lang.fetchtime}: </span>{$fetchtime}s{else}&nbsp;{/if}{if !empty($md5)} {$md5}{/if}</nobr>
+    </td>
+    <td align="right">
+        <form action="trace.php" method="get">
+            <input type="hidden" name="videodburl" value="{$url}"/>
+            <input type="hidden" name="videodbreload" value="Y"/>
+            <input type="submit" value="Reload" class="button"/>
+        </form>
+    </td></tr>
+    </table>
+</td></tr>
+</table>
+{$page}