Add .gitignore to exclude runtime and large files

.gitignore

@@ -0,0 +1,24 @@
+# Composer / PHP
+vendor/
+composer.lock
+
+# Node / npm (if you ever keep source files)
+node_modules/
+npm-debug.log
+
+# Docker runtime data
+db-data/
+docker-compose.override.yml
+
+# WordPress runtime files
+wp-data/
+wp-content/
+*.log
+
+# OS / editor artefacts
+.DS_Store
+Thumbs.db
+*.swp
+.idea/
+.vscode/
+