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/composer/autoload_namespaces.php

@@ -0,0 +1,13 @@
+<?php
+
+// autoload_namespaces.php @generated by Composer
+
+$vendorDir = dirname(dirname(__FILE__));
+$baseDir = dirname($vendorDir);
+
+return array(
+    'Spreadsheet' => array($vendorDir . '/pear/spreadsheet_excel_writer'),
+    'OLE' => array($vendorDir . '/pear/ole'),
+    'Console' => array($vendorDir . '/pear/console_getopt'),
+    '' => array($vendorDir . '/pear/pear-core-minimal/src'),
+);