perf(data): LazyFrame-native openquant.data path + benchmark scaffold

Cargo.toml

@@ -1,3 +1,6 @@
 [workspace]
 members = ["crates/openquant", "crates/pyopenquant"]
 resolver = "2"
+
+[patch.crates-io]
+pyo3-polars = { path = "vendor/pyo3-polars" }

README.md

@@ -41,7 +41,7 @@ python3 scripts/check_bench_thresholds.py --baseline benchmarks/baseline_benchma
 ## Research Flywheel (Python + Rust)
 ```bash
 # Python env + bindings
-uv venv --python 3.11 .venv
+uv venv --python 3.13 .venv
 uv sync --group dev
 uv run --python .venv/bin/python maturin develop --manifest-path crates/pyopenquant/Cargo.toml
 
@@ -51,6 +51,9 @@ uv run --python .venv/bin/python python experiments/run_pipeline.py --config exp
 
 # Rust notebook-companion smoke
 cargo run -p openquant --example research_notebook_smoke
+
+# Python pipeline micro-benchmark (for speed demos)
+uv run --python .venv/bin/python python python/benchmarks/benchmark_pipeline.py --iterations 30 --bars 2048
 ```
 
 ## Crate Layout

crates/openquant/Cargo.toml

@@ -20,6 +20,7 @@ statrs = "0.16"
 rand_distr = "0.4"
 nalgebra = "0.32"
 csv = "1"
+polars = { version = "0.46", default-features = false, features = ["strings", "lazy"] }
 
 [dev-dependencies]
 csv = "1"