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/setasign/fpdf/composer.json

@@ -0,0 +1,24 @@
+{
+    "name": "setasign/fpdf",
+    "homepage": "http://www.fpdf.org",
+    "description": "FPDF is a PHP class which allows to generate PDF files with pure PHP. F from FPDF stands for Free: you may use it for any kind of usage and modify it to suit your needs.",
+    "type": "library",
+    "keywords": ["pdf", "fpdf"],
+    "license": "MIT",
+    "authors": [
+        {
+            "name": "Olivier Plathey",
+            "email": "oliver@fpdf.org",
+            "homepage": "http://fpdf.org/"
+        }
+    ],
+    "autoload": {
+        "classmap": [
+            "fpdf.php"
+        ]
+    },
+    "require": {
+        "ext-zlib": "*",
+        "ext-gd": "*"
+    }
+}