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/pear/pear-core-minimal/README.rst

@@ -0,0 +1,26 @@
+******************************
+Minimal set of PEAR core files
+******************************
+
+This repository provides a set of files from ``pear-core``
+that are often used in PEAR packages.
+
+It follows the `pear-core`__ repository and gets updated whenever a new
+PEAR version is released.
+
+It's meant to be used as dependency for composer packages.
+
+__ https://github.com/pear/pear-core
+
+==============
+Included files
+==============
+- ``OS/Guess.php``
+- ``PEAR.php``
+- ``PEAR/Error.php``
+- ``PEAR/ErrorStack.php``
+- ``System.php``
+
+
+``PEAR/Error.php`` is a dummy file that only includes ``PEAR.php``,
+to make autoloaders work without problems.