The emscripten glue's `var ENV = {};` never merged Module.ENV, so boot.ts's
Module.ENV.KICAD_TRACE was a silent no-op — and since environ_get on a pthread
proxies to the main thread, the app/UI thread's getenv read the (empty) main
ENV. Net: KICAD_TRACE never arrived and every KI_TRACE was a no-op.
scripts/common/patch-env-shim.mjs post-processes each generated <app>.js to
merge Module.ENV into ENV (idempotent; runtime no-op when unset), wired into
docker/build.sh's per-app host post-process next to the dyncall-shim inject.
Replaces a fragile manual glue edit re-applied after every build. Verified:
symbol-editor eager load now emits KI_TRACE_SYM_CHOOSER fatLoad timing.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
