feat(benchmark): add module exports

Public API exports for the benchmark module.

src/veritext/benchmark/__init__.py

@@ -0,0 +1,12 @@
+"""Benchmark module for quality tracking and regression detection."""
+
+from veritext.benchmark.models import BenchmarkRun, RegressionReport
+from veritext.benchmark.runner import Benchmark
+from veritext.benchmark.storage import BenchmarkStorage
+
+__all__ = [
+    "Benchmark",
+    "BenchmarkRun",
+    "BenchmarkStorage",
+    "RegressionReport",
+]