Fix browser test: mock provider.listModels and provider.getUsage RPCs

The ChatView browser test mock WS handler didn't handle
provider.listModels and provider.getUsage RPCs for fork's extra
providers, causing React Query "data cannot be undefined" errors
that crashed the test environment.

Author: aaditagrawal

apps/web/src/components/ChatView.browser.tsx

@@ -552,6 +552,12 @@ function resolveWsRpc(body: WsRequestEnvelope["body"]): unknown {
       pr: null,
     };
   }
+  if (tag === WS_METHODS.providerListModels) {
+    return { models: [] };
+  }
+  if (tag === WS_METHODS.providerGetUsage) {
+    return { quotaSnapshots: [] };
+  }
   if (tag === WS_METHODS.projectsSearchEntries) {
     return {
       entries: [],