create-ven-client and create-bl-client accept :query-param-extensions, a
map of route name to param keys sent on the query string although the
embedded spec does not declare them. The new extra-query-params
interceptor runs after Martian's query-params interceptor.

lib-version now reads META-INF/energy.grid-coordination/clj-oa3/VERSION,
which build.clj also reads; it previously reported 0.2.1. Version 0.5.0.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>