Add copyright headers to configuration files

Extended copyright headers to SQL, YAML, and JSON configuration files:
- config/docker/init.sql (SQL comment block)
- docker-compose.yml (YAML comment)
- composer.json and src/composer.json (JSON _comment field)

All files validated and tested successfully.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

composer.json

@@ -1,4 +1,5 @@
 {
+    "_comment": "Web Crawler - Composer Configuration | Copyright (c) 2025 Martin Kiesewetter <mki@kies-media.de> | https://kies-media.de",
     "name": "web-crawler/app",
     "description": "Web Crawler Application with Parallel Processing",
     "type": "project",