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/spreadsheet_excel_writer/.travis.yml

@@ -0,0 +1,25 @@
+language: php
+php:
+  - 5.6
+  - 7.0
+  - 7.1
+  - 7.2
+  - 7.3
+  - 7.4
+
+cache:
+  directories:
+    - $HOME/.composer/cache
+    - $HOME/.cache/cache
+    - build/cache
+
+install:
+  - composer install --prefer-dist
+  - mkdir -p build/cache
+
+script:
+  - php vendor/bin/phpunit --coverage-clover build/logs/clover.xml
+  - vendor/bin/php-cs-fixer --cache-file=build/cache/.php_cs.cache --diff --dry-run --stop-on-violation --verbose fix
+
+after_success:
+  - travis_retry php vendor/bin/php-coveralls