Add docker-compose.override.yml to gitignore

Supports local dev overrides without shipping them to customers.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: DAdjadj

.gitignore

@@ -2,3 +2,4 @@ data/
 *.pyc
 __pycache__/
 .env
+docker-compose.override.yml