Add stage 2: Vue/TypeScript PWA shell with auth-gated routing

Backend: new migration adds users.email_verified_at (null = unverified);
registration leaves it null, and the register/login/me payloads now expose
email_verified and email_verified_at.

Frontend (web/): Vite + Vue 3 + TypeScript PWA (vite-plugin-pwa). Pinia auth
store keeps the token in localStorage and validates it via GET /api/me on
load. vue-router guards redirect unauthenticated visitors to /login,
preserving the intended path; /register creates an account and signs in
immediately (with the email unverified). Placeholder home page, minimal
styling, generated icons. Dev server proxies /api to the API.

docker-compose.yml gains an optional "web" service (profile: frontend) so
`docker compose --profile frontend up -d` runs the dev server alongside the
API; `docker compose up -d` still starts the API alone.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

web/src/views/HomeView.vue

@@ -0,0 +1,35 @@
+<script setup lang="ts">
+import { useAuthStore } from '../stores/auth'
+
+const auth = useAuthStore()
+</script>
+
+<template>
+  <section class="card">
+    <h1>Your todo list</h1>
+    <p class="muted">
+      Placeholder page. The list and its items arrive in the next stage — for now
+      this screen just proves you are authenticated against the REST API.
+    </p>
+
+    <div v-if="!auth.emailVerified" class="notice">
+      Your email address <strong>{{ auth.user?.email }}</strong> has not been
+      verified yet. Verification will be added in a later stage.
+    </div>
+
+    <dl class="facts">
+      <div>
+        <dt>Signed in as</dt>
+        <dd>{{ auth.user?.email }}</dd>
+      </div>
+      <div>
+        <dt>Account created</dt>
+        <dd>{{ auth.user?.created_at ?? '—' }}</dd>
+      </div>
+      <div>
+        <dt>Email verified</dt>
+        <dd>{{ auth.emailVerified ? 'yes' : 'no' }}</dd>
+      </div>
+    </dl>
+  </section>
+</template>