[gkennos]

Summary

This is to fix issue described in #52

Checklist

• Applied exactly one label (breaking, feature, fix, dependencies, or chore)
• Tests pass locally (uv run pytest -q)
• Lint passes (uv run ruff check .)

[Copilot]

🟡 Changes recommended

Stopping at the node budget does not explicitly close the underlying streaming SQLAlchemy result, potentially leaving its cursor open while the supplied session remains active.

1 open issue

• Close the SQLAlchemy result when traversal ends early · New

What changed in this PR

This PR addresses #52 by stopping traversal when the node budget is discovered, reducing unnecessary edge materialization for high-fan-out concepts.

Changes:

• Track discovered nodes and stop edge consumption as soon as max_nodes is reached.
• Add opt-in batched fetching to KnowledgeGraph.iter_edges.
• Test traversal limits, edge closure over returned nodes, and early iterator termination.

File	Description
tests/​test_traverse.py	Adds regression tests for capped traversal and streaming options.
src/​omop_graph/​graph/​traverse.py	Enforces the discovery budget during expansion and closes edge generators.
src/​omop_graph/​graph/​kg.py	Adds optional batched result fetching for edge iteration.

_{Review effort: Balanced}