test: add test infrastructure for frontend and server

- Frontend: vitest.config.ts with vue plugin + jsdom, dummy component test
- Server: in-memory SQLite test DB factory + Hono testClient helper + smoke test
- CI: add pnpm audit and server coverage threshold steps
- Root: vitest workspace config for multi-project test discovery

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

frontend/src/components/__tests__/DummyComponent.test.ts

@@ -0,0 +1,19 @@
+import { describe, it, expect } from 'vitest'
+import { mount } from '@vue/test-utils'
+import DummyComponent from './DummyComponent.vue'
+
+describe('DummyComponent', () => {
+  it('renders the message prop as text content', () => {
+    const wrapper = mount(DummyComponent, {
+      props: { message: 'BOTFIGHTS' },
+    })
+    expect(wrapper.text()).toBe('BOTFIGHTS')
+  })
+
+  it('renders different message', () => {
+    const wrapper = mount(DummyComponent, {
+      props: { message: 'Stack sats, fight bots' },
+    })
+    expect(wrapper.text()).toBe('Stack sats, fight bots')
+  })
+})

frontend/src/components/__tests__/DummyComponent.vue

@@ -0,0 +1,7 @@
+<script setup lang="ts">
+defineProps<{ message: string }>()
+</script>
+
+<template>
+  <div class="dummy">{{ message }}</div>
+</template>

frontend/src/test-setup.ts

@@ -0,0 +1,2 @@
+// Frontend test setup for @vue/test-utils + jsdom
+// Add global test utilities and mocks here as needed