Clarify artifact serialization limit in comments

Expanded comments to explain the rationale for limiting artifact serialization to the first 100 programs, detailing the impact on memory usage and worker initialization speed. No functional changes were made.

Author: codelion

openevolve/process_parallel.py

@@ -343,7 +343,12 @@ def _create_database_snapshot(self) -> Dict[str, Any]:
         }
 
         # Include artifacts for programs that might be selected
-        # (limit to reduce serialization overhead)
+        # IMPORTANT: This limits artifacts (execution outputs/errors) to first 100 programs only.
+        # This does NOT affect program code - all programs are fully serialized above.
+        # With max_artifact_bytes=20KB and population_size=1000, artifacts could be 20MB total,
+        # which would significantly slow worker process initialization. The limit of 100 keeps
+        # artifact data under 2MB while still providing execution context for recent programs.
+        # Workers can still evolve properly as they have access to ALL program code.
         for pid in list(self.database.programs.keys())[:100]:
             artifacts = self.database.get_artifacts(pid)
             if artifacts: