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/vendor/guzzlehttp/guzzle/src/Exception/BadResponseException.php

@@ -0,0 +1,27 @@
+<?php
+namespace GuzzleHttp\Exception;
+
+use Psr\Http\Message\RequestInterface;
+use Psr\Http\Message\ResponseInterface;
+
+/**
+ * Exception when an HTTP error occurs (4xx or 5xx error)
+ */
+class BadResponseException extends RequestException
+{
+    public function __construct(
+        $message,
+        RequestInterface $request,
+        ResponseInterface $response = null,
+        \Exception $previous = null,
+        array $handlerContext = []
+    ) {
+        if (null === $response) {
+            @trigger_error(
+                'Instantiating the ' . __CLASS__ . ' class without a Response is deprecated since version 6.3 and will be removed in 7.0.',
+                E_USER_DEPRECATED
+            );
+        }
+        parent::__construct($message, $request, $response, $previous, $handlerContext);
+    }
+}