feat(arty): introduce runtime facade and core crates

[martintmk]

Introduces the initial arty runtime facade and intentionally empty arty_io_core contract crate at version 0.2.0. arty re-exports thread-awareness types through arty::core and exposes selected Tick primitives through independent time and test-util features. arty_io_core is reserved for stable contracts that integrate external I/O drivers with the runtime. The change also adds minimal design, I/O, panic-safety, and stabilization policies, feature-surface tests, and aligned Arty logo assets.

[github-actions]

✅ Version increments look sufficient

cargo semver-checks compared the 2 crate(s) this PR publishes against their previous version-bump commit in git history. Every version increment is sufficient for the detected API changes.

Crate	Baseline	Baseline commit	This PR	Minimum required	Status
arty	new crate	—	0.2.0	0.2.0	✅ ok
arty_io_core	new crate	—	0.2.0	0.2.0	✅ ok

This check is informational and does not block the merge.

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[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 100.0%. Comparing base (d37be41) to head (a9dffce).

Additional details and impacted files

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  Coverage   100.0%   100.0%           
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  Files         583      583           
  Lines       62930    62930           
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  Hits        62930    62930           

Flag	Coverage Δ
linux	99.9% <ø> (-0.1%)	⬇️
linux-arm	100.0% <ø> (ø)
scheduled	?
windows	100.0% <ø> (?)

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[Copilot]

🟡 Changes recommended

The new public-surface test uses size_of without bringing it into scope, and should be adjusted to avoid relying on implicit availability.

Once you've addressed the issues Copilot identified, you can request another Copilot review.

Pull request overview

Introduces the initial arty runtime facade crate and an intentionally empty arty_core foundation crate, establishing a small, feature-gated public surface that primarily re-exports existing workspace primitives.

Changes:

• Added arty and arty_core crates at 0.2.0, including crate docs and packaging/metadata setup.
• Implemented arty as a facade re-exporting thread_aware_core under arty::core and selected tick types behind time / test-util features.
• Added public-surface tests to validate the feature-gated facade.

File summaries

File	Description
crates/arty/tests/public_surface.rs	Adds compile-time surface checks for feature-gated re-exports.
crates/arty/src/lib.rs	Defines the arty facade modules and feature-gated re-exports.
crates/arty/README.md	Adds generated crate README describing features and policies.
crates/arty/docs/STABILIZATION.md	Documents stabilization policy for re-exported dependencies.
crates/arty/docs/PANICS.md	Documents panic/unwind safety policy expectations.
crates/arty/docs/IO.md	Documents I/O ownership/injection policy.
crates/arty/docs/DESIGN.md	Documents high-level design intent.
crates/arty/Cargo.toml	Adds crate metadata, features, deps, and external-types allowlist.
crates/arty_core/src/lib.rs	Introduces empty foundation crate with crate-level docs.
crates/arty_core/README.md	Adds generated README for the foundation crate.
crates/arty_core/Cargo.toml	Adds crate metadata and coverage-gate configuration for empty crate.
Cargo.toml	Registers arty and arty_core in the workspace dependency set.
Cargo.lock	Records new workspace packages in the lockfile.

Review details

• Files reviewed: 12/13 changed files
• Comments generated: 1
• Review effort level: Lite

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[Copilot]

🔵 Needs a closer look

The added public-surface tests reference size_of without explicitly bringing it into scope, which should be fixed to keep the tests self-contained and unambiguous.

Review details

Suppressed comments (2)

crates/arty/tests/public_surface.rs:19

• size_of is used without being brought into scope, which makes the test rely on an implicit import rather than being self-contained. Prefer explicitly importing core::mem::size_of (or qualifying it) where it’s used.

    use arty::time::{Clock, Delay, FutureExt, PeriodicTimer, SimpleClock, Stopwatch, Timeout};

crates/arty/tests/public_surface.rs:35

• size_of is referenced here without being in scope. Using a fully-qualified path keeps this test independent of any surrounding imports.

    let _ = size_of::<arty::time::ClockControl>();

• Files reviewed: 17/19 changed files
• Comments generated: 0 new
• Review effort level: Lite

[Copilot]

🟢 Approval recommended

The changes are additive and low-risk (new crates + re-exports + docs/tests), with only a minor documentation consistency nit noted.

Review details

• Files reviewed: 20/22 changed files
• Comments generated: 1
• Review effort level: Lite

[Copilot]

🔵 Needs a closer look

The repo root README adds arty but omits listing the newly introduced arty_io_core, leaving the primary-crates index inconsistent with the PR’s scope.

Review details

Suppressed comments (1)

README.md:33

• The repo root crate list introduces arty, but it doesn’t list the newly added arty_io_core crate even though it’s part of this PR (and similar “_core” crates like thread_aware_core are listed). This makes discovery inconsistent for users browsing the primary crates.

- [`allocation_hints`](./crates/allocation_hints/README.md) - Allocator-independent heap ownership and scoped allocation hints.
- [`arty`](./crates/arty/README.md) - Single-threaded, thread-aware application runtime.
- [`bytesbuf`](./crates/bytesbuf/README.md) - Types for creating and manipulating byte sequences.

• Files reviewed: 20/21 changed files
• Comments generated: 0 new
• Review effort level: Lite