Generic long-lived backend (template_override='hap_backend_longlived') for apps
whose primary path holds connections open: streaming, large up/downloads,
persistent sessions. Both primary and SSE backends tuned long-lived (no
http-server-close, http-no-delay, 6h server/tunnel/keep-alive). Differs from
hap_backend_websocket (which only long-lives the SSE variant).
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
