slang-server: unknown JSON-RPC methods get no reply; custom commands go via executeCommand

slang-server v0.3.1 (hudson-trading SystemVerilog LSP) registers custom commands such as slang.getScope and slang.getInstancesOfModule only as workspace/executeCommand commands. Sending one as a bare JSON-RPC method gets no response at all: the server only logs 'WARN: <-/- slang.getScope (not found)' to stderr, with no -32601 error, so a client awaiting that id hangs. It also loads .slang/server.json only from the initialize rootUri. Rooting at a subdir gave empty getScope results, and stderr shows 'Server initialized at <root>'. Give hand-written LSP clients per-request timeouts and capture stderr.