vst-bench-dataset-host: Sample-Free VST3 Fixture and Offline Validation Host

A self-authored, sample-free VST3 test instrument, offline runner, localhost JSON-RPC host, and validation scripts for the separately archived vst-bench-ml package. This archive adds complete source-snapshot verification without requiring access to private Git repositories. External SDK source must be retrieved separately. No compiled binaries, SDK tree, or generated audio is included. Qualifying sample-free fixture outputs are separately dedicated under CC0-1.0 as described in the bundled output licence; that does not relicense the source archive or external dependencies. Documentation correction (23 September 2026): updated the source archive README publication links and regenerated its integrity manifest. Executable source, fixture inputs, expected outputs, and dependency locks are unchanged.