chore(release): bump version to 0.6.4 - #1656

0.6.3 → 0.6.4:

• INHERITS writes up to 12× faster: one query per (child, parent) label pair that actually occurs, instead of the full P²+P grid fan-out (perf(inherits): group INHERITS writes by the label pairs that occur #1652, @mollyjester)
• Six bug(indexer): parser audit roundup — context attribution, wrong Module names, missing declarations and duplicate call records across 12 languages #1538 parser-audit fixes: Rust braced-use lists and clean import paths, C# generic bases un-shredded, Python relative-import package level, Dart import aliases, Scala parameterless defs, Ruby singleton methods (fix(parsers): six #1538 audit findings — Rust/C#/Python/Dart imports and bases, Scala/Ruby missing declarations #1654)
• cgc diagram in the canonical smoke matrix + machine-output console redirect no longer leaks a captured stream (fix(cli): diagram in the canonical smoke matrix; scoped machine-output console redirect #1655)

Full integration suite green at the release commit: 89 passed / 0 failed.