Problem

Building the standalone esminiJS Emscripten/WASM target
(EnvironmentSimulator/Libraries/esminiJS, per its build.sh / CMakeLists.txt)
compiles all objects but then fails to link:

undefined symbol: ESMINI_GIT_REV
undefined symbol: ESMINI_GIT_TAG
undefined symbol: ESMINI_GIT_BRANCH
undefined symbol: ESMINI_BUILD_VERSION

Those symbols are referenced by CommonMini.cpp and defined in a generated
version.cpp (produced from version.cpp.in by CommonMini/version.cmake). The
full esmini build generates it via CommonMini/CMakeLists.txt, but the standalone
esminiJS target never triggers that generation, so version.cpp is missing from
the link.

Fix

Invoke version.cmake from the esminiJS CMakeLists.txt exactly the way
CommonMini/CMakeLists.txt already does
(cmake -DESMINI_BUILD_VERSION=... -P version.cmake). The existing
COMMONMINI_SOURCES glob then picks up the generated CommonMini/version.cpp, so
no source-list change is needed. 20 lines, one file.

Under a shallow checkout git describe yields nothing and the values resolve to
"N/A", which is harmless.

Verification

With this change the esminiJS target builds and links standalone via
emcmake cmake -G Ninja -DCMAKE_BUILD_TYPE=Release + SINGLE_FILE=1, producing a
working esmini.js. I ran it in headless Chromium: get_road_geometry() returns
lane surfaces / lane centers and step_frame() advances entities, with reset()
restarting the run (endless-loop playback).

Refs #357.

Note

Happy to follow up on distribution (an npm package / a prebuilt WASM release asset)
if that's useful — there is currently no published artifact, which is the main thing
keeping downstream projects from consuming esminiJS directly.