chore(rsr): machine-readable artefacts, Justfile, community-health (#4) #16

	# SPDX-License-Identifier: MPL-2.0
	# Copyright (c) 2026 Jonathan D.A. Jewell (hyperpolymath) <j.d.a.jewell@open.ac.uk>
	#
	# Rust CI for arghda-core. Inline, self-contained — does not depend on
	# hyperpolymath/standards/.github/workflows/rust-ci-reusable.yml because
	# that reusable has been red on every call since 2026-05-27 (verified
	# against absolute-zero / ambientops / cloudguard-cli / conflow /
	# conative-gating callers; standards repo's own check runs are also
	# red). When the standards reusable is fixed, this file can be
	# replaced with a 3-line wrapper calling it.

	name: Rust CI

	on:
	push:
	branches: [main, master]
	pull_request:

	concurrency:
	group: ${{ github.workflow }}-${{ github.ref }}
	cancel-in-progress: true

	permissions:
	contents: read

	jobs:
	build-and-test:
	name: Build + test + clippy + fmt
	runs-on: ubuntu-latest
	steps:
	- name: Checkout
	uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6.0.2

	- name: Cache cargo registry + git + target
	uses: actions/cache@0057852bfaa89a56745cba8c7296529d2fc39830 # v4
	with:
	path: \|
	~/.cargo/registry
	~/.cargo/git
	target
	key: cargo-${{ runner.os }}-${{ hashFiles('Cargo.lock') }}
	restore-keys: \|
	cargo-${{ runner.os }}-

	- name: Toolchain
	run: \|
	rustup show
	rustc --version
	cargo --version
	rustup component add clippy rustfmt

	- name: cargo fmt --check
	run: cargo fmt --all -- --check

	- name: cargo build
	run: cargo build --all-targets --verbose

	- name: cargo test
	run: cargo test --all-targets --verbose

	- name: cargo clippy
	run: cargo clippy --all-targets -- -D warnings

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