# ECP-0018: discovery mode toggles in Tauri UI

## Status
Draft

## Context
Discovery is now opt-in (DHT/mDNS with DNS disabled by default). Users need an in-app way to enable discovery without setting environment variables.

## Decision
Add a discovery settings section to the Tauri viewer UI with toggles for DHT, mDNS, and DNS (pkarr relay). The selected modes are sent with MoQ connect, share, and catalog discovery commands.

## Details
- UI stores discovery state (DHT/mDNS/DNS) and emits a comma-separated string (e.g. `dht,mdns`).
- Manual MoQ connect, catalog discovery, and Share use the selected discovery config.
- If no modes are enabled, discovery remains off and share bundles must include full endpoint addresses.

## Consequences
- Users can opt in to decentralized discovery without env vars.
- DNS discovery remains explicit and off by default.