docs(release): describe Apple Silicon nightly package

Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>

4 files changed, 15 insertions, 9 deletions

diff --git a/AGENTS/ARCH.md b/AGENTS/ARCH.md
index 0e5d2e9..2fa02bd 100644
--- a/AGENTS/ARCH.md
+++ b/AGENTS/ARCH.md
@@ -189,13 +189,17 @@ including paginated results, before either build starts. It never creates or
 deletes the release and preserves its tag, title and notes. GitHub's generated
 source downloads remain available.
 
-Compiler and plugin jobs run independently on Ubuntu 24.04 x86_64, checking out
-the push SHA. The compiler uses LLVM/Clang 23 from apt.llvm.org, Release and
-EMBEDDED settings, Pandoc, and the existing `release` target. It extracts and
-checks the archive, then runs a small OUTPUT program with the packaged binary.
-The plugin uses Node.js 22, `npm ci --ignore-scripts` and `npm run package`, then
-checks VSIX contents. Each job uploads directly after its own checks pass;
-failure in one does not block the other. No Actions artifacts are uploaded.
+The Linux compiler and plugin jobs use Ubuntu 24.04 x86_64; the macOS compiler
+job uses a macOS 15 arm64 runner. All three check out the push SHA and run
+independently after cleanup. Both compiler jobs use LLVM/Clang 23, Release and
+EMBEDDED settings, Pandoc, and the existing `release` target. Linux obtains its
+toolchain from apt.llvm.org; macOS uses Homebrew's LLVM 23. Each job extracts
+and checks its archive, then runs a small OUTPUT program with the packaged
+binary. The macOS check also verifies arm64 and rejects non-system dynamic
+libraries. The plugin uses Node.js 22, `npm ci --ignore-scripts` and
+`npm run package`, then checks VSIX contents. Each job uploads directly after
+its own checks pass; failure in one does not block the others. No Actions
+artifacts are uploaded.
 Cleanup and uploads check main's current SHA to avoid modifying nightly for a
 superseded push. The workflow uses `GITHUB_TOKEN` with `contents: write`.
 Compiler package names retain the existing commit-based version; the VSIX uses
diff --git a/README.md b/README.md
index 8a9ccc8..2956124 100644
--- a/README.md
+++ b/README.md
@@ -4,7 +4,7 @@ A compiler for CIE Pseudocode (A Level 9618 Computer Science)
 
 [Usage quick reference](doc/cpsc.1.md) · [Build guide](doc/build.md) · [Installation and releases](doc/install.md)
 
-Download the Linux x86_64 compiler package and VS Code extension from [Nightly Build](https://github.com/ovfor4/cie-pseudocode-compiler/releases/tag/nightly-build). The compiler uses EMBEDDED mode and needs no LLVM installation. Each push to `main` removes the previous attachments before rebuilding both packages; each package appears when its build and checks finish.
+Download the Linux x86_64 or macOS 15+ Apple Silicon compiler package and VS Code extension from [Nightly Build](https://github.com/ovfor4/cie-pseudocode-compiler/releases/tag/nightly-build). The compiler uses EMBEDDED mode and needs no LLVM installation. Each push to `main` removes the previous attachments before rebuilding all three packages; each package appears when its build and checks finish.
 
 Details can be found here: [Pseudocode Guide for Teachers](https://www.cambridgeinternational.org/Images/697401-2026-pseudocode-guide-for-teachers.pdf)
 
diff --git a/doc/install.md b/doc/install.md
index f1e55d9..b734f77 100644
--- a/doc/install.md
+++ b/doc/install.md
@@ -2,6 +2,8 @@
 
 To build from source, follow [build.md](build.md). For command-line usage, see [cpsc.1.md](cpsc.1.md). Run build commands from the project root; package installation commands run from the extracted package directory.
 
+The [Nightly Build](https://github.com/ovfor4/cie-pseudocode-compiler/releases/tag/nightly-build) provides EMBEDDED release archives for Linux x86_64 and macOS 15+ Apple Silicon, plus the VS Code extension. The macOS archive is named `cpsc-VERSION-Darwin-arm64.tar.xz`; use the Unix release package instructions below after extraction.
+
 ## Linux installation
 
 After configuring and building, install the compiler and manual with:
diff --git a/plugin/README.md b/plugin/README.md
index 1718945..3eeac5e 100644
--- a/plugin/README.md
+++ b/plugin/README.md
@@ -6,7 +6,7 @@ VS Code support for this project's `.cps` files. Requires VS Code 1.85 or newer
 
 ## Install
 
-Download the VSIX from [Nightly Build](https://github.com/ovfor4/cie-pseudocode-compiler/releases/tag/nightly-build). The same release provides the Linux x86_64 compiler with execution support.
+Download the VSIX from [Nightly Build](https://github.com/ovfor4/cie-pseudocode-compiler/releases/tag/nightly-build). The same release provides Linux x86_64 and macOS 15+ Apple Silicon compiler packages with execution support.
 
 In the Extensions panel, choose **... > Install from VSIX...** and select `cie-pseudocode-0.1.0.vsix`, or run: