[samgbafa]

Summary

• Configure cargo-dist to build the aarch64-apple-darwin target on the supported macOS 15 ARM64 runner (macos-15).
• Bump the node release version to 1.25.21 and add the Monica-approved Apple Silicon binary release note. Details: TC-2728.
• This addresses the unsupported runner label that caused the 1.25.20 aarch64-apple-darwin release job to fail. No tag is moved and the failed 1.25.20 workflow is not rerun.

Production scope

This is a binaries-only release patch. The normal 1.25.21 tag-triggered workflow will publish release binaries and a GitHub Release after merge. The production node CVM remains on 1.25.20; this PR does not include or authorize a CVM deployment or promotion. Any later CVM deployment requires separate authorization.

Validation

• cargo metadata --locked --no-deps --format-version 1 confirms aarch64-apple-darwin maps to macos-15.
• cargo metadata --manifest-path test/m1-realdata-e2e/Cargo.toml --locked --no-deps --format-version 1
• cargo fmt --all --check
• git diff --check
• CI must pass at the exact PR head before handoff; no merge/tag/release/deploy by this author.