feat: plugin skeleton for Shopware 6.6 and 6.7 with CI and release pipeline

- composer.json (MIT, shopware/core ~6.6.0 || ~6.7.0, PHP ^8.2), plugin class, placeholder icon
- PR checks and release workflow taken over from AeonDumpManager; phpunit runs as a 6.6/6.7 matrix
- CHANGELOG, LICENSE, README, CLAUDE.md, smoke test

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

.gitignore

@@ -1,54 +1,39 @@
-# ---> Symfony
-# Cache and logs (Symfony2)
-/app/cache/*
-/app/logs/*
-!app/cache/.gitkeep
-!app/logs/.gitkeep
+# PHP
+vendor/
+composer.phar
+.phpunit.result.cache
+.phpunit.cache/
+.php-cs-fixer.cache
 
-# Email spool folder
-/app/spool/*
+# Symfony / Shopware
+/var/
+/public/bundles/
+/public/assets/
+/custom/
+/src/Shopware/Platform
 
-# Cache, session files and logs (Symfony3)
-/var/cache/*
-/var/logs/*
-/var/sessions/*
-!var/cache/.gitkeep
-!var/logs/.gitkeep
-!var/sessions/.gitkeep
+# Frontend
+*.vite/
+**/public/administration/assets/
+**/public/static/js/
 
-# Logs (Symfony4)
-/var/log/*
-!var/log/.gitkeep
+# Environment
+.env
+.env.local
+.env.*.local
 
-# Parameters
-/app/config/parameters.yml
-/app/config/parameters.ini
+# Agent skills (symlinked via skills.sh, tracked through skills-lock.json)
+/.agents/
+/.claude/
+/.qwen/
+/.opencode/
+/.scratch/
 
-# Managed by Composer
-/app/bootstrap.php.cache
-/var/bootstrap.php.cache
-/bin/*
-!bin/console
-!bin/symfony_requirements
-/vendor/
-
-# Assets and user uploads
-/web/bundles/
-/web/uploads/
-
-# PHPUnit
-/app/phpunit.xml
-/phpunit.xml
-
-# Build data
-/build/
-
-# Composer PHAR
-/composer.phar
-
-# Backup entities generated with doctrine:generate:entities command
-**/Entity/*~
-
-# Embedded web-server pid file
-/.web-server-pid
+# IDE
+.idea/
+.vscode/
+*.swp
 
+# OS
+.DS_Store
+Thumbs.db