Fix immutable provenance flags for Shiftedx Bench v0.5.1

Release Shiftedx Bench v0.5.0 with Shiftedx Agent Harness

fix: render unestablished effective context

Record immutable benchmark revision in run manifests

v0.3.0: add post-publish model-card qualification

v0.2.1: make 128K the default quant-gate ceiling

Add v0.2.0 lightweight full-window quant gate

Publish Shiftedx Bench v0.1.0