fix(explorer): various fixes

.changeset/unlucky-icons-wonder.md

@@ -0,0 +1,10 @@
+---
+"@latticexyz/explorer": patch
+---
+
+Fixed an issue where the `observer` Viem client decorator required an empty object arg when no options are used.
+
+```diff
+-client.extend(observer({}));
++client.extend(observer());
+```

packages/explorer/src/observer/decorator.ts

@@ -14,7 +14,7 @@ export type ObserverOptions = {
 export function observer<transport extends Transport, chain extends Chain, account extends Account>({
   explorerUrl = "http://localhost:13690",
   waitForStateChange,
-}: ObserverOptions): (
+}: ObserverOptions = {}): (
   client: Client<transport, chain, account>,
 ) => Pick<WalletActions<chain, account>, "writeContract"> {
   const emit = createBridge({ url: `${explorerUrl}/internal/observer-relay` });