The opaque-workspace-identifier refactor (e6044264) added a `b64_` prefix
to base64-encoded workspace IDs in route builders. Two app tests still
expected the unprefixed form and failed in CI.
The opaque-workspace-identifier refactor (e6044264) added a `b64_` prefix
to base64-encoded workspace IDs in route builders. Two app tests still
expected the unprefixed form and failed in CI.