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/lib/smarty/custom/function.html_rating.php

@@ -0,0 +1,72 @@
+<?php
+/**
+ * Smarty plugin
+ * @package Smarty
+ * @subpackage plugins
+ * @author  Andreas Goetz   <cpuidle@gmx.de>
+ */
+
+/**
+ * Smarty {html_rating} function plugin
+ *
+ * File:       function.html_rating.php<br>
+ * Type:       function<br>
+ * Name:       html_rating<br>
+ * Purpose:    Prints out a rating as a series of stars<br>
+ * Input:<br>
+ *           - name       (optional) - string default "checkbox"
+ *           - value      (required) - string
+ *           - id         (optional) - checkbox id (name is default)
+ * @return string
+ */
+function smarty_function_html_rating($params, &$smarty)
+{
+    $name = 'rating';
+    $value = null;
+
+    $extra = '';
+
+    foreach($params as $_key => $_val) {
+        switch($_key) {
+            case 'name':
+            case 'id':
+            case 'value':
+                $$_key = $_val;
+                break;
+
+            default:
+                if(!is_array($_val)) {
+                    $extra .= ' '.$_key.'="'.smarty_function_escape_special_chars($_val).'"';
+                } else {
+                    $smarty->trigger_error("rating: extra attribute '$_key' cannot be an array", E_USER_NOTICE);
+                }
+                break;
+        }
+    }
+
+    // assign default id
+    if (empty($id)) $id = $name;
+
+    $_output = '';
+
+    $rcv = 0;
+    if (is_numeric($value))
+    {   $rcv = ceil($value); }
+    
+    for ($i=0; $i< $rcv; $i++)
+    {
+        $_output .= '<img src="'.img('goldstar.gif').'" width="20" height="18" />';
+    }
+    for ($i=0; $i< (10 - $rcv); $i++)
+    {
+        $_output .= '<img src="'.img('greystar.gif').'" width="20" height="18" />';
+    }
+
+    $_output .= $extra;
+
+    $_output .= " ($value)";
+
+    return $_output;
+}
+
+?>