Add backup file patterns to gitignore

Ignore *.from_server, *.backup, and *.bak files

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

.gitignore

@@ -50,3 +50,8 @@ htmlcov/
 
 # Logs
 *.log
+
+# Backup files
+*.from_server
+*.backup
+*.bak