lsrpc is local IPC (IDE ↔ language_server binary), not an upstream protocol. cloudcode-pa.googleapis.com does not serve gRPC/lsrpc endpoints. Restores antigravityRetryLoop + streamGenerateContent path which was working. Removes antigravity_lsrpc.go (upstream caller) and lsrpc_test cmd. Keeps lsrpc_handler.go (server side, receives IDE connections).