Mark v2.1.3-beta

Automated release from 87c7c38124dd2cbe3dbe9f2aaa2312a4a351d7dd.

Verification:

Build provenance (SLSA-3):

gh attestation verify Mark_2.1.3-beta_aarch64.dmg --owner xronocode

Cosign keyless signature:

cosign verify-blob \
  --bundle Mark_2.1.3-beta_aarch64.dmg.bundle \
  --certificate-identity-regexp 'https://github.com/xronocode/mark/.*' \
  --certificate-oidc-issuer https://token.actions.githubusercontent.com \
  Mark_2.1.3-beta_aarch64.dmg

DMG SHA-256 sidecar published as Mark_2.1.3-beta_aarch64.dmg.sha256.

CycloneDX SBOMs published for both Node renderer and Rust backend
dependency closures. NOTICES-{node,rust}.md attribution lists
shipped alongside.

Updater: ed25519-signed feed (latest.json + Mark_2.1.3-beta_aarch64.app.tar.gz) shipped.
tauri-plugin-updater verifies against the embedded pubkey before applying. To upgrade
outside the in-app updater:

brew upgrade --cask mark