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>

tests/test_network.py

@@ -20,10 +20,13 @@ def test_denoising_mlp_output_shape():
     x_t = torch.randn(B, 9)
     t = torch.rand(B)
     cond_cont = torch.randn(B, 9)
-    cond_cat = torch.stack([
-        torch.randint(0, 5, (B,)),
-        torch.randint(0, 3, (B,)),
-    ], dim=1)
+    cond_cat = torch.stack(
+        [
+            torch.randint(0, 5, (B,)),
+            torch.randint(0, 3, (B,)),
+        ],
+        dim=1,
+    )
     out = model(x_t, t, cond_cont, cond_cat)
     assert out.shape == (B, 9)