Document completed human ground-truth audit and synchronized results

[DavidBakerEffendi]

Description

Completes issue #58 by documenting the first human review of all 158 current cases and publishing a synchronized exact-range Bifrost-versus-LSP development run.

Key Changes:

• Add a dedicated audit-status page with coverage, review procedure, trust boundary, and evaluation-promotion path.
• Present UsageBench as Bifrost's recurring LSP-parity and regression suite, with future competitors supported by the analyzer-neutral contract.
• Replace the legacy 16 July figures across the homepage, result pages, case comparison, and all language summaries.
• Report the shared 131-case matrix: 84 exact for both, 32 exact only for Bifrost, 11 exact only for the LSP, and 4 exact for neither.
• Preserve the development/evaluation boundary: the corpus remains analyzer-informed and legacy_unattributed pending a second independent review, preregistration, and freeze.

Touch Points:

• docs/src/content/docs/ground-truth-review.md
• docs/src/content/docs/{index.mdx,overview.md,methodology.md,reproduce.md}
• docs/src/content/docs/results/{index.md,case-comparison.md}
• docs/src/content/docs/languages/*.md
• docs/astro.config.mjs
• README.md
• benchmarks/README.md
• benchmarks/reviews/2026-07-17-DavidBakerEffendi.md

Synchronized Run:

• UsageBench: 78e66e5dd3589d4543f1b19a8b3566fa9afd644a
• Bifrost origin/master: 782522b245fc86e3d39b1cdc0488553a1d262212
• Bifrost full corpus: 133 exact of 152 scoreable, 3 expected gaps, 16 other non-exact, 2 unsupported, 4 not planned
• Primary LSP profiles: 95 exact of 131 scoreable, 10 position-unverified, 26 hard, 23 unsupported, 4 not planned
• Runner errors: 0 across Bifrost and all ten primary LSP profiles

Validation:

• cargo run -- validate benchmarks/cases (35 documents)
• RUSTDOC=/Users/dave/.rustup/toolchains/stable-aarch64-apple-darwin/bin/rustdoc cargo test (106 passed; doctests passed)
• npm run check
• npm run build (18 pages)
• Rendered inspection of the homepage, synchronized result, and case-comparison pages

Closes #58