v0.6.0

openCypher TCK conformance 94.4% → 99.9% (3878/3880 scenarios, 0 wrong-result). Full details in CYPHER_COVERAGE.md.

Added

• Parser replaced: ANTLR4-generated grammar instead of the hand-rolled pest grammar — the foundation for everything else in this release.
• marsdb-capi (C ABI) and marsdb-go (cgo binding).
• List-valued node/edge properties, and $parameters naming a list or a map.
• SET n = {...} / SET n += {...}; MERGE/CREATE/DELETE/SET/REMOVE can now chain directly into each other; ON MATCH/ON CREATE in either order in MERGE.
• Variable-length relationship patterns: binding [r*1..3] to a real list variable, matching against an already-bound list, and inline properties on the hop itself.
• Named-path capture over patterns mixing a variable-length hop with other hops.
• exists { MATCH ... RETURN ... }, the full nested-subquery form of existential subqueries.
• CALL proc(args) [YIELD ...] against a pluggable ProcedureProvider.
• A real manual: knoguchi.github.io/marsdb, README badges, and measured test coverage in CI.

Fixed

• Integer arithmetic overflow now returns a query error instead of panicking.
• duration.between()/duration.inSeconds() component-accessor math, and combined ISO-8601 date-time duration string parsing.
• The null literal now types as Kind::Unknown, fixing several wrongly-rejected compile-time cases.
• A variable-length hop's own traversed edges weren't excluded from later hops of the same pattern, causing a silent double-count in some named-path-capture patterns.
• List-concat (+) type inference wrongly rejected a later CREATE off a concatenated node/relationship list.
• marsdb-go's list-valued property JSON round-trip.
• marsdb-python's PropertyValue conversion was missing a match arm for Map.

Full changelog: CHANGELOG.md