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/elegant/js/Autocompleter.js

@@ -0,0 +1,42 @@
+/**
+ * Enhanced Ajax.Autocompleter with support for parameters array and custom completion code
+ */
+Ajax.Autocompleter2 = Class.create(Autocompleter.Base, {
+  initialize: function(element, update, url, options) {
+    this.baseInitialize(element, update, options);
+    this.options.asynchronous  = true;
+    this.options.onComplete    = this.onComplete.bind(this);
+    this.options.defaultParams = this.options.parameters || null;
+    this.url                   = url;
+  },
+
+  // allow parameters array
+  getUpdatedChoices: function() {
+    this.startIndicator();
+
+    var entry = encodeURIComponent(this.options.paramName) + '=' +
+      encodeURIComponent(this.getToken());
+
+    this.options.parameters = this.options.callback ?
+      this.options.callback(this.element, entry) : entry;
+
+    if(this.options.defaultParams) {
+      // if defaultParams is a string, keep as is and don't convert
+      var defaultParams = Object.isString(this.options.defaultParams) ? this.options.defaultParams : Object.toQueryString(this.options.defaultParams);
+
+      this.options.parameters += '&' + defaultParams;
+    }
+
+    new Ajax.Request(this.url, this.options);
+  },
+
+  // allow custom completion code
+  onComplete: function(request) {
+    if (this.options.updateContent) {
+      this.options.updateContent(request);
+      this.stopIndicator();
+    }
+    else this.updateChoices(request.responseText);
+  }
+});
+