fix(ci): remove aarch64-pc-windows-msvc from release matrix

Cross-compilation of crypto crates (ring, aws-lc-sys) for Windows ARM64
from Linux runners fails due to missing SDK headers and unsupported
ARM architecture flags in GCC.

- Remove aarch64-pc-windows-msvc from build matrix
- Update README download table (5 targets instead of 6)
- Fix deprecated criterion::black_box -> std::hint::black_box

Author: bug-ops

.github/workflows/release.yml

@@ -41,10 +41,10 @@ jobs:
             target: x86_64-pc-windows-msvc
             archive: zip
             use_cross: false
-          - os: ubuntu-latest
-            target: aarch64-pc-windows-msvc
-            archive: zip
-            use_cross: true
+          # aarch64-pc-windows-msvc removed: cross-compilation from Linux
+          # fails for crypto crates (ring, aws-lc-sys) that require
+          # Windows ARM64 SDK headers unavailable in cross containers.
+          # Re-enable when GitHub provides hosted Windows ARM64 runners.
     steps:
       - uses: actions/checkout@v6
       - uses: dtolnay/rust-toolchain@stable

README.md

@@ -33,7 +33,6 @@ Download from [GitHub Releases](https://github.com/bug-ops/zeph/releases/latest)
 | macOS | x86_64 | `zeph-x86_64-apple-darwin.tar.gz` |
 | macOS | aarch64 | `zeph-aarch64-apple-darwin.tar.gz` |
 | Windows | x86_64 | `zeph-x86_64-pc-windows-msvc.zip` |
-| Windows | aarch64 | `zeph-aarch64-pc-windows-msvc.zip` |
 
 ### Docker
 

crates/zeph-channels/benches/markdown_performance.rs

@@ -1,4 +1,5 @@
-use criterion::{BenchmarkId, Criterion, Throughput, black_box, criterion_group, criterion_main};
+use criterion::{BenchmarkId, Criterion, Throughput, criterion_group, criterion_main};
+use std::hint::black_box;
 use zeph_channels::markdown::{markdown_to_telegram, utf8_chunks};
 
 fn generate_text(size: usize, pattern: &str) -> String {