Replace one-shot HTTP POST sendPrompt with a persistent ephemeral
terminal per session. Terminal auto-starts on session select, stays
running in background when modal is closed, and gets killed on
session switch or page unload.
- Add sendInput() to useEphemeralTerminal (text + Enter as separate WS messages)
- useTranscriptDebug owns terminal lifecycle (create/dispose on select/switch)
- ResumeTerminalButton receives shared terminal prop, only toggles modal
- UserInput shows "Starting terminal..." when not ready
- Add "New Session" button that starts a fresh agent session
- beforeunload sends sendBeacon to kill terminal on page close
josedario87
016e92ffe5