fix post-rebase: update stale Js_top_worker_rpc refs, cppo-gate ppx_template_generated
- findlibish.mli: use Js_top_worker.Impl.dynamic_cmis (RPC module removed)
- worker.ml: use Impl.dcs_url instead of Toplevel_api_gen.dcs_url
- x-ocaml/src/jtw_client: convert to cppo for OxCaml-only
ppx_template_generated field in Query_protocol.Compl
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>