Function createRelayTiers

createRelayTiers(
storage: StorageLike,
defaults?: Partial<Record<RelayTier, readonly string[]>>,
): RelayTiers
Create the relay tier configuration the shell and kehto both read.

kehto's RelayConfigHooks knows discovery, super and outbox; kernl adds apps, the tier that serves applet manifests. The configuration is persisted at kernl:relays:v1 and changes$ replays the current value to new subscribers so UI and adapters can share one source.
Parameters
- storage: StorageLike
  Where the user's relay choices are persisted.
- defaults: Partial<Record<RelayTier, readonly string[]>> = {}
  Per-tier overrides applied over DEFAULT_RELAY_TIERS when nothing is persisted.
Returns RelayTiers
The tier configuration.
Example
```
const tiers = createRelayTiers(localStorage, { apps: ['wss://relay.example'] });
tiers.add('outbox', 'wss://relay.mine');
tiers.get().outbox; // ['wss://relay.mine']
```