Update .gitignore to exclude sensitive files

Add rules for credentials, SQL dumps, and backup files
to prevent accidental exposure in public repository.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

.gitignore

@@ -1,3 +1,9 @@
 cms/uploads/
 cms/data/cache/
 .DS_Store
+
+# Credenciales y configuración sensible
+cms/data/settings.dat.php
+.docker/.env
+.docker/*.sql
+.docker/*.backup