v2.18.9 — TestEdgeEmbeddingsE2E isolation fix; 0 unit test failures

v2.18.9 (2026-09-10)

Fix: TestEdgeEmbeddingsE2E isolation — run-scoped assertions, full wipe in setup

TestEdgeEmbeddingsE2E assertions embedded == N were comparing the total count
of ALL embeddings in the session-scoped container against the expected count for
the current test run. Other tests in the session (ledger E2E, etc.) left rows in
rdf_edges and kg_EdgeEmbeddings. Fix: setup now wipes nodes, rdf_labels,
rdf_props, rdf_edges, and kg_EdgeEmbeddings; assertions check run-prefixed
counts via direct SQL rather than the global result["embedded"] counter.

Result: 0 failures (was 4 pre-existing), 7876 passed.