fix: \VueQueryPlugin\ possibly dead dependency (#195)

Clarify that @tanstack/vue-query is a required peer dependency of
@wagmi/vue, not a dead import. Add a comment in main.ts explaining the
rationale, and document the dependency in ARCHITECTURE.md and
landing/AGENTS.md.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

landing/src/main.ts

@@ -1,6 +1,8 @@
 import './assets/styles/main.sass';
 import { createApp } from 'vue';
 import { WagmiPlugin } from '@wagmi/vue';
+// VueQueryPlugin is required by @wagmi/vue — it provides the TanStack Query context
+// that Wagmi uses internally for its reactive data hooks (useAccount, useConnect, etc.).
 import { VueQueryPlugin } from '@tanstack/vue-query';
 import { createHarbConfig } from '@harb/web3';
 import App from './App.vue';