Build Entrypoints

builds/ contains build system entrypoints.

It does not contain product app shells.

Core rule:

Build Entrypoint invokes.
App Shell composes.

The Phase 8.2 skeleton records authoritative build hosts without moving current build files:

builds/
  esp_idf/
  pio_nrf52/
  linux_cmake/

Build entrypoints are thin wrappers. They may call into app shells and adapt build-host conventions, but they must not assemble Chat, Map, Team, or GPS runtime object graphs, choose UX packs, define board facts, or implement product behavior.

Current transitional paths remain valid until wrapper migration is proven:

removed root esp_idf
removed root esp_pio
Linux app-local CMake paths such as removed root linux_sim and removed root linux_rpi

This directory is intentionally documentation-only in Phase 8.2.