66ee7e31ac
Update ci-build-fast.yml to use MIR-precise mode, which reads actual compiler MIR to build a ground-truth call graph. This stubs 1,060 mono items (vs 799 with syn-based analysis), reducing fresh build wall time by 27.2% on a 48-core server (vs 9.1% with syn alone). Update docs with new benchmark table showing both modes.