feat(types): Complete strict static analysis and typing track

tests/test_token_viz.py

@@ -1,7 +1,4 @@
 """Tests for context & token visualization (Track: context_token_viz_20260301)."""
-from typing import Generator
-from unittest.mock import patch
-import pytest
 
 import ai_client
 from ai_client import _add_bleed_derived, get_history_bleed_stats