Splits socket/tracking into their own subdirectories and pulls the hello
action registration out into its own module, matching the one-module-per-
folder pattern; build.sh now outputs into build/macos instead of the repo root.
Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
C/C++ extension built directly against the vendored Cockos reaper-sdk
headers (no Rust/reaper-rs wrapper layer). Loads, registers a test
action, and confirms via REAPER's console — confirmed working in
REAPER 2026-07-15.
Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>