openai/gpt-chat-latest → B (3:1)

Side B fixes a functional data-model and UI integration issue: Reddit child imports now attach entities directly under the intended parent via `apply_entity_under_parent`, preserves imported entity metadata, updates ranking panel rendering to use the tree for child titles, and wires the new API through callers. It also adds integration tests covering SSE updates and children fetch behavior, whereas Side A is a UI refinement that changes row color gradients from list position to score-based normalization with focused unit tests but does not address core functionality.