v1.5.0: smooth 1.5.0 — AE 2025 support, Mac Phase 1/2-C + Windows Phase 2-D

Mac (universal, x86_64 + arm64):
- Row-block parallelism (Phase 1)
- Rust core port via FFI staticlib (Phase 2-C)

Windows (x64):
- Same Rust staticlib as Mac, built with +crt-static for AE
  plugin distribution (no VC++ redist dep on end-user machine)

Artifacts:
- Mac/release/smooth.Mac.1.5.0.AE2025.{universal,arm64,x86_64}.zip
- win/release/smooth.Win.1.5.0.AE2025.x64.zip