Apply ruff format and document lint/type tooling in CLAUDE.md

First repo-wide ruff format pass, plus a note in CLAUDE.md to run
ruff and ty periodically.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

giant/data/loader.py

@@ -51,10 +51,18 @@ def iter_file_chunks(path: str | Path) -> Iterator[dict[str, np.ndarray]]:
 
 
 _COND_COLS = [
-    "event_id", "pdg",
-    "pre_x", "pre_y", "pre_z", "pre_E",
-    "pre_dx", "pre_dy", "pre_dz",
-    "material", "layer_id", "child_track_ids",
+    "event_id",
+    "pdg",
+    "pre_x",
+    "pre_y",
+    "pre_z",
+    "pre_E",
+    "pre_dx",
+    "pre_dy",
+    "pre_dz",
+    "material",
+    "layer_id",
+    "child_track_ids",
 ]