ci(release): add aarch64 Linux wheel targets

Mirror the atomr workspace's release.yml — add native aarch64 Linux
wheel builds on `ubuntu-22.04-arm` runners for both manylinux (glibc)
and musllinux. Previously ARM Linux users had to install from the
sdist; they now get prebuilt wheels matching the x86_64 coverage.

README + RELEASING.md updated to reflect the expanded wheel matrix.

Author: cognect

.github/workflows/release.yml

@@ -7,8 +7,10 @@ name: Release
 #
 # This workflow:
 #   1. Runs the local release-pipeline gate (`cargo xtask verify`).
-#   2. Builds Python wheels (manylinux x86_64, musllinux x86_64,
-#      macOS universal2, Windows x86_64) and an sdist.
+#   2. Builds Python wheels (manylinux x86_64 + aarch64, musllinux
+#      x86_64 + aarch64, macOS universal2, Windows x86_64) and an
+#      sdist. aarch64 Linux wheels are built natively on
+#      `ubuntu-22.04-arm` runners.
 #   3. Creates the GitHub Release with the artifacts attached.
 #   4. Publishes every publishable Rust crate to crates.io in
 #      dependency order (with rate-limit retry).
@@ -78,15 +80,30 @@ jobs:
       fail-fast: false
       matrix:
         include:
-          # Linux glibc + musl, x86_64. ARM Linux users install from sdist.
+          # Linux glibc + musl, x86_64 + aarch64. maturin uses
+          # manylinux/musllinux containers under the hood; the
+          # `manylinux: auto` flag picks the right base image.
           - os: ubuntu-latest
             target: x86_64-unknown-linux-gnu
             python-target: x86_64
             manylinux: auto
+          # aarch64 Linux glibc — built natively on a GitHub-hosted
+          # ARM runner so we don't have to cross-compile inside the
+          # x86_64 manylinux container. Mirrors the atomr workspace.
+          - os: ubuntu-22.04-arm
+            target: aarch64-unknown-linux-gnu
+            python-target: aarch64
+            manylinux: auto
           - os: ubuntu-latest
             target: x86_64-unknown-linux-musl
             python-target: x86_64
             manylinux: musllinux_1_2
+          # aarch64 Linux musl — also built natively on the ARM
+          # runner, mirroring the glibc coverage.
+          - os: ubuntu-22.04-arm
+            target: aarch64-unknown-linux-musl
+            python-target: aarch64
+            manylinux: musllinux_1_2
           # macOS — universal2 yields a single fat wheel covering
           # both x86_64 and arm64.
           - os: macos-latest

README.md

@@ -431,12 +431,12 @@ and the rationale for keeping it out of CI.
 ## Releasing
 
 `v*.*.*` git tags trigger a single `release.yml` pipeline that runs
-the verify gate, builds Python wheels (manylinux x86_64, musllinux
-x86_64, macOS universal2, Windows x86_64) + an sdist, creates a
-GitHub Release, publishes the workspace crates to crates.io in
-topological order, and uploads wheels + sdist to PyPI via trusted
-publishing. See [`RELEASING.md`](RELEASING.md) for the end-to-end
-flow.
+the verify gate, builds Python wheels (manylinux x86_64 + aarch64,
+musllinux x86_64 + aarch64, macOS universal2, Windows x86_64) + an
+sdist, creates a GitHub Release, publishes the workspace crates to
+crates.io in topological order, and uploads wheels + sdist to PyPI
+via trusted publishing. See [`RELEASING.md`](RELEASING.md) for the
+end-to-end flow.
 
 ## Learn more
 

RELEASING.md

@@ -43,7 +43,7 @@ path-dep version pins inside `[workspace.dependencies]`, refreshes
 |----------------------------------|-------------------------------|--------------|
 | `ci.yml`                         | PRs + pushes to `main`        | fmt + clippy + test (8 feature configs) + verify gate + semver-checks (PR-only) + Python build/test + doc upload |
 | `version-bump.yml`               | Push to `main`                | Conventional-Commits → `cargo xtask bump` → commit `chore(release)` → tag `vX.Y.Z` |
-| `release.yml`                    | Tag `v*` push                 | xtask verify → build wheels (manylinux/macOS/Windows) + sdist → GitHub Release with auto-notes → publish-crates → publish-pypi |
+| `release.yml`                    | Tag `v*` push                 | xtask verify → build wheels (manylinux x86_64 + aarch64 / musllinux x86_64 + aarch64 / macOS universal2 / Windows x86_64) + sdist → GitHub Release with auto-notes → publish-crates → publish-pypi |
 | `docs.yml`                       | Push to `main`, tag `v*`      | rustdoc → GitHub Pages |
 
 `release.yml` honors three `workflow_dispatch` inputs for testing: