[frontend] section — bundled default frontend settings.
When enabled = True, deepagent deploy copies a pre-built React
chat UI into the deployment alongside the agent. An [auth]
section is required in this case — pick "supabase" or "clerk"
for real per-user auth, or set provider = "anonymous" explicitly
to ship the UI with an open API.
Subtitle shown under the app name in the header and on the empty-state hero. Falls back to a generic default when unset.
Suggestion chips shown on the empty-state. Falls back to the bundled defaults when unset.