v2.18.0 — Bug fixes, VLP/adjacency corrections, spec-hygiene gates

v2.18.0 (2026-09-07)

Bug fixes across Cypher VLP, adjacency indexing, SQL bridge, and spec-hygiene gates

27 previously-failing tests now pass. Key fixes: BuildKG never populated ^KG for
default-graph edges (IRIS SQL %GetData returns $C(0) for empty-string VARCHAR NOT NULL,
not ""); VLP source-ID extraction heuristic picked the property-key string instead of the
node ID; SQL bridge had column-name typos unreachable without a live container. Five
spec-hygiene gates added to prevent these categories of regression.

Fixes

• TraversalBuild.BuildKG: $ZStrip(edgeGraph, "*C") strips the $C(0) sentinel
  before comparing to "", so default-graph edges are now correctly written to
  ^KG("out", 0, s, p, o). Without this, sync()/BuildKG ran without error but
  left ^KG empty, silently breaking all multi-hop BFS and variable-length-path queries.
• LedgerApply.OpCreateRel: missing ) in WriteAdjacency(...) call (introduced by
  spec-214 graph-param addition) — caused compile error at container startup that was
  swallowed by || true. Fixed to WriteAdjacency(tS, tP, tO, ..WeightOf(tQuals), tGKey).
• VLP source-ID extraction (_engine/query.py): replaced broken "first SQL param
  that isn't a schema name" heuristic with full-SQL DISTINCT source_alias.node_id query
  using all original params. The old heuristic picked 'id' (a property key string) as the
  source node ID when rdf_props JOINs appeared before the Cartesian JOIN boundary.
  Also added fast-path for WHERE source_alias.node_id = ? patterns to avoid a DB round-trip.
• _engine/fhir.py column name typos: sqlid_column → sql_table + id_column,
  viavia_source → via_source in three SQL statements. Caused SQLCODE -29 on all
  map_sql_table and list_table_mappings calls.
• IVF Cypher translation: kg_IVF(?, ?, k, nprobe) parameters now inlined as SQL
  literals — IRIS does not support ? parameters inside JSON_TABLE(stored_proc(...)).
• String subscript ('hello'[1..4]): routes to SUBSTRING instead of JSON array
  logic when base is a string literal.
• VLP relationship property filter ([r*1..2 {weight: 10}]): applied in
  _execute_var_length_labeled via incoming-edge qualifier lookup; was silently ignored.
• Label isolation JOIN for mapped SQL table nodes: translate_node_pattern now skips
  rdf_labels JOIN for nodes registered in mapped_node_aliases — external SQL tables
  have no node_id column, causing SQLCODE -29.
• test_attrs_roundtrip: attrs.error → attrs.get("error") (dict, not object).
• bm25_build test: "node_id, text" → ["node_id", "text"] (list, not string).
• test_store_protocol test sync: TestPurgeRawBefore, TestDropGraph,
  TestUpdateSpoUniqueConstraint updated to match current implementation semantics
  (PurgeResult return type, multi-step FK-safe delete, 3-execute DROP+ADD sequence).

Spec-Hygiene Gates (Principle VIII — constitution v1.3.0)

Four gates added to prevent the root-cause categories from recurring:

• Gate 1 (tests/conftest.py): missing IRIS container → pytest.fail instead of
  pytest.skip. Silent fake-green is no longer possible.
• Gate 2 (scripts/enterprise-container.sh): compile-all exits non-zero on any
  ObjectScript compile error; || true removed from up sequence.
• Gate 3 (scripts/enterprise-container.sh): adjacency smoke test on every container
  startup — create_edge + sync() + BFS, asserts result non-empty.
• Gate 4 (tests/unit/test_store_protocol.py, tests/unit/test_spec_hygiene_gates.py):
  test_mock_has_all_protocol_methods uses inspect to diff GraphStore members against
  MockGraphStore at unit-test time (no container). test_fhir_sql_columns_match_schema
  parses INSERT/SELECT DML in fhir.py and cross-references column names against
  CREATE TABLE in schema.py.