parseIfcUrl, buildIfcUrl, toRawUrl extracted from viewer.html into
viewer-url.js so they can be imported and tested independently.
viewer.html imports from the module. 32 Node test-runner tests in
tests/test_viewer_url.mjs cover all three functions across GitHub,
GitLab, Forgejo/Gitea, SSH user@ prefix, and round-trip cases.
Caught a bug: + (selector union operator) was being URL-encoded as
%2B in buildIfcUrl; fixed by adding .replace(/%2B/g, "+") alongside
the existing comma fix, in both viewer-url.js and syncCameraUrl.
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>