feat: add RoPE positional embeddings implementation in llama.ipynb

- Implement Rotary Positional Embeddings (RoPE) with separate cosine/sine components
- Add vectorized computation of inverse frequencies for RoPE
- Include tensor slicing utilities for even/odd column separation
- Update dependencies in pyproject.toml and uv.lock

pyproject.toml

@@ -12,6 +12,8 @@ dependencies = [
     "llm",
     "tqdm>=4,<5",
     "ipykernel",
+    "torch==2.8.0",
+    "matplotlib==3.10.6",
 ]
 
 [project.optional-dependencies]