LSP custom/initializeAPISession never responds in stdio mode (7.0.0-dev.20260518.1 / 20260522.1)

[re-thc]

Summary

custom/initializeAPISession appears to hang (no response) when tsgo is started with --lsp --stdio.

Repro

1. Start tsgo --lsp --stdio.
2. Send initialize request and initialized notification.
3. Send request:

{"jsonrpc":"2.0","id":2,"method":"custom/initializeAPISession","params":{"pipe":"/tmp/tsgo-api-test.sock"}}

Expected

A JSON-RPC response (or explicit JSON-RPC error) and API socket creation.

Actual

No response before timeout; requested pipe is not created.

Versions observed

• @typescript/native-preview package 7.0.0-dev.20260518.1 (server reports typescript-go 7.0.0-dev.20260518.1)
• latest package tag currently resolves to server typescript-go 7.0.0-dev.20260522.1 and still shows same behavior.

Notes

I also see tsgo --lsp --socket ... prints only stdio is supported, so stdio appears to be the only LSP mode in this build and this directly blocks LSP->API session bridging clients.