RpcGroup.toLayer types each handler's requirements by scanning every RPC in
the group, so the cost grows with handlers x RPCs. Near 200 WebSocket methods
it crossed TypeScript's instantiation limit, the layer's requirements fell
back to `any`, and typecheck failed (TS2589 / TS377030).

Register the handlers through two disjoint groups built from the same
middleware-wrapped RPCs, which halves the cost. Handler behavior, contracts,
and the layer's requirement, error, and output types are unchanged.

Fixes #22364

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