#spawnTcp reserved a port, released it, spawned the adapter, then immediately
connected. On WSL2 with networkingMode=mirrored the Windows relay keeps
accepting connections to the just-released reservation port for tens of ms, so
the first connect bound a ghost socket instead of js-debug. Gate the connect on
the adapter announcing its listening port on stdout (as vscode-js-debug does
from inside its listen callback) so we only connect once the child owns the
port; this also drains stdout, which nothing else consumes in tcp mode.
Separately, the message reader only rejected pending requests from its catch, so
a clean stream end (the ghost socket dropped after we wrote initialize) left
requests and event waiters pending until their own timeout. Route both the
reader end and adapter exit through a single #failConnection that rejects
pending requests and wakes event waiters, turning every transport failure into
an immediate "DAP connection closed" error instead of a silent 30s timeout.
Fixes#6055
roboomp
07019e6c61