fix: resolve estate gates and Rust/Creusot debt (#87)

[arena-ai-coding-agent]

Closes #87

Summary

Resolves the only open issue (#87) and the two persistently red required checks on (Governance — Guix packaging, Documentation — missing pages). After 50+ consecutive Documentation failures and every Governance run red for Guix, this PR makes both green while preserving the estate Zig FFI and Idris2 ABI boundaries.

Changes

• docs: restore Documenter sources — docs/make.jl references index.md/api-*.md but only *.adoc existed since f1b44a3 (Markdown→AsciiDoc). Restore the Markdown sources from f1b44a3^ so makedocs(doctest=true) can find its pages. Fixes the Documentation workflow (Build docs (Documenter, with doctests)).
• chore(pkg): Guix primary + Containerfile — add guix.scm/manifest.scm (Guix, julia/zig/rust/openssl/pkg-config, mpl2.0) and Containerfile (cgr.dev/chainguard/wolfi-base + RUN) to satisfy scripts/check-package-policy.sh (RULED 2026-05-18, Guix primary / sealed-container escape, no Nix). Fixes Governance Guix primary / Nix fallback policy.
• chore(init): fill {{PROJECT_UNIQUE_STRENGTH}} in .machine_readable/bot_directives/methodology.a2ml and delete REQUIRES_INITIALISATION.adoc.
• feat(crypto): Rust + Creusot reconciliation (debt: reconcile Rust crypto component with Creusot after PR backlog clears #87) — inventory at docs/CRYPTO-CREUSOT-VERIFICATION.adoc, creusot-contracts optional dependency (feature = "creusot", cfg(creusot) shim), #[cfg_attr(creusot, ensures(...))] on all 6 FFI exports + 6 length getters (status-code ranges, length constants), and #[cfg(creusot)] mod creusot_hybrid_spec with hybrid_valid = ed_ok && dil_ok. Normal cargo build/test stays hermetic (attributes discarded); cargo check --features creusot typechecks contracts. Zig (zig/, ffi/zig/) and Idris2 (axiom-abi.ipkg) untouched (git diff --stat origin/main shows no edits there).
• feat(ci): Creusot workflow + evidence — .github/workflows/creusot.yml (cargo check gate + best-effort Why3, artifact build/creusot_evidence.json) and scripts/creusot-evidence.sh + just verify-crypto/creusot-evidence.

Verification

• git diff --stat origin/main -- zig/ ffi/ axiom-abi.ipkg → empty (preservation)
• just build-crypto / just test-crypto (Rust unit tests, 7 tests) — green via julia-test.yml which already builds the cdylib
• cargo check --features creusot — blocks on ill-formed contracts
• bash scripts/creusot-evidence.sh → build/creusot_evidence.json
• Documentation now has docs/src/*.md so julia --project=docs docs/make.jl can locate pages

Estate Gates

• Governance: expects green (Guix packaging now present)
• Documentation: expects green (pages now present)
• Julia Test Gate: already green, unchanged (crypto cdylib built before Pkg.test)
• Creusot: new workflow, first run will appear below

[coderabbitai]

Important

Review skipped

Bot user detected.

To trigger a single review, invoke the @coderabbitai review command.

⚙️ Run configuration

Configuration used: Organization UI

Review profile: ASSERTIVE

Plan: Advanced

Run ID: 94932f73-99d8-4705-83c1-ed768b0bd7d4

You can disable this status message by setting the reviews.review_status to false in the CodeRabbit configuration file.

Use the checkbox below for a quick retry:

• 🔍 Trigger review

---

Thanks for using CodeRabbit! It's free for OSS, and your support helps us grow. If you like it, consider giving us a shout-out.

❤️ Share

• X
• Mastodon
• Reddit
• LinkedIn

_{Comment @coderabbitai help to get the list of available commands.}