engine.sx now contains only pure logic: parsing, morph, swap, headers,
retry, target resolution, etc. orchestration.sx contains the browser
wiring: request execution, trigger binding, SSE, boost, post-swap
lifecycle, and init. Dependency is one-way: orchestration → engine.
Bootstrap compiler gains "orchestration" as a separate adapter with
deps on engine+dom. Engine-only builds get morph/swap without the
full browser runtime.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>