Fix Intel component warning in Apple-silicon builds

[SDSLeon]

Summary

• prune foreign node-pty and legacy better-sqlite3 native prebuilds from each thin package before signing
• keep the target PTY prebuild and existing executable-bit/native-module validation
• reject Apple-silicon app bundles containing Mach-O binaries without an arm64 slice in CI

Verification

• simulated arm64 after-pack bundle contains only arm64 Mach-O binaries
• simulated x64 after-pack bundle retains the required x86_64 binaries
• pnpm run lint
• pnpm run typecheck
• formatting and diff checks