♻️ refactor(frontend): split HealthDashboard into smart wrapper + dumb View for state-based stories (#33)

SRP split: HealthDashboardView (presentational, props-based) + HealthDashboard (smart wrapper, useFetch). Enables 4 Storybook stories per state + unit testability per branch. Existing testids preserved, Playwright tests still pass.

Co-authored-by: Gabriel Radureau <arcodange@gmail.com>
Co-committed-by: Gabriel Radureau <arcodange@gmail.com>

frontend/components/HealthDashboardView.vue

@@ -0,0 +1,30 @@
+<script setup lang="ts">
+export interface HealthInfo {
+  status: string
+  version: string
+  uptime_seconds: number
+  timestamp: string
+}
+
+defineProps<{
+  data: HealthInfo | null | undefined
+  pending: boolean
+  error: { message: string } | null | undefined
+}>()
+</script>
+
+<template>
+  <section data-testid="health-dashboard">
+    <h2>Server Health</h2>
+    <p v-if="pending" data-testid="health-loading">Loading...</p>
+    <p v-else-if="error" data-testid="health-error">
+      Error loading health: {{ error.message }}
+    </p>
+    <ul v-else-if="data" data-testid="health-info">
+      <li><strong>Status:</strong> <span data-testid="health-status">{{ data.status }}</span></li>
+      <li><strong>Version:</strong> {{ data.version }}</li>
+      <li><strong>Uptime:</strong> {{ data.uptime_seconds }} seconds</li>
+      <li><strong>Last check:</strong> {{ data.timestamp }}</li>
+    </ul>
+  </section>
+</template>