CORE-001: Core workspace scaffold and verification gate

Context

bayan-core is empty. Every later core work package builds on the workspace layout, lint configuration and verification gate created here, so the conventions set now matter for years. Read ADR-0005 (no floating point in layout, deterministic math), ADR-0006 (no unsafe outside binding crates, toolchain pinning) and ADR-0017 (exact pins, minimum age) before starting.

Objective

A Cargo workspace with the crate skeletons needed in Phase 0, strict lints that enforce determinism and safety rules, and a single command, cargo xtask verify, that CI runs on Linux, Windows and macOS and for wasm32.

Scope

In scope

• Cargo.toml workspace: edition 2024, resolver 3, [workspace.package] (repository URL, rust-version matching the toolchain, license = "GPL-3.0-or-later WITH AdditionRef-BayanDocs-App-Store-Permission" per ADR-0003 §4, the SPDX 3.0 form that cargo-deny accepts), [workspace.dependencies] with exact =x.y.z requirements, [workspace.lints] with unsafe_code = "forbid" (overridden only in bayan-ffi and bayan-wasm), and a curated Clippy set (all warnings denied in CI, a pedantic subset).
• rust-toolchain.toml: the latest stable Rust release that is at least 24 hours old (record its version and release date in the pull request), components rustfmt and clippy, target wasm32-unknown-unknown.
• clippy.toml: disallowed-methods for floating-point transcendental and platform math methods on f32/f64 (sin, cos, tan, asin, acos, atan, atan2, sinh, cosh, tanh, exp, exp2, exp_m1, ln, log, log2, log10, ln_1p, powf, powi, cbrt, hypot), with a message pointing to bayan-units; disallowed-types for std::collections::HashMap and HashSet (allowed only via #[expect] with a justification where iteration order cannot affect output).
• Crate skeletons with crate-level documentation stating their responsibility and layer: bayan-units, bayan-opc, bayan-xml, bayan-crdt, bayan-model, bayan-engine, bayan-ffi, bayan-wasm, bayan-cli. Layout: crates/<name>/, xtask/, lab/ (empty README), fuzz/ (empty README), spikes/ (README explaining that spikes are excluded from release builds).
• xtask with cargo xtask verify running, in order: cargo fmt --check, cargo clippy --workspace --all-targets --all-features -- -D warnings, cargo test --workspace --locked, a wasm32 build of every crate that must support WebAssembly, cargo doc --workspace --no-deps with warnings denied, and cargo deny check (tool installed in CI at a pinned version with checksum verification). Leave clearly named hooks for the X-003 checks and for future determinism checks.
• CI workflow running cargo xtask verify on ubuntu-24.04, windows-latest and macos-latest (arm64), following the workflow conventions of ADR-0017 (SHA-pinned actions, minimal permissions, timeouts). Caching only with first-party actions.
• .cargo/config.toml with [registry] global-min-publish-age = "1 day" (inactive until Rust 1.100, see ADR-0017).
• Update this repository’s AGENTS.md with the real commands.

Out of scope

• Any functionality inside the crates (later WPs).
• License files: LICENSE, LICENSES/ and REUSE.toml already exist; keep reuse lint passing (the REUSE CI job comes with X-001).
• Supply-chain scripts (X-003).

Deliverables

Workspace, crate skeletons, xtask, configuration files, CI workflow, updated AGENTS.md.

Acceptance criteria

• AC-1 cargo xtask verify passes locally and in CI on all three operating systems; the wasm32 build passes.
• AC-2 A test or documented demonstration shows that calling f64::sin in a core crate fails the lint, and that unsafe in a non-binding crate fails to compile.
• AC-3 All dependencies (including xtask dependencies) are exact-pinned, at least 24 hours old, on the ADR-0017 license allowlist, and justified in the pull request; the transitive count is reported.
• AC-4 Each crate’s documentation states its layer and the layering rule from the architecture document.
• AC-5 CI completes in under 15 minutes.

Verification

cargo xtask verify; CI links for the three platforms.

Notes and pitfalls

• Keep xtask dependencies minimal (prefer the standard library and std::process::Command).
• cargo-deny needs a deny.toml; add a minimal one (X-003 completes it).

Escalate if

The latest stable toolchain is younger than 24 hours and the previous one lacks something you need; or a lint rule required by ADR-0005 cannot be expressed in Clippy.