feat(02-06): Account tab in SettingsView + QR code in TotpEnrollment (GAPs 3, 5)

- frontend/package.json: add qrcode@1.5.4 to runtime dependencies
- TotpEnrollment.vue: import QRCode; generate data URL in startSetup(); render img tag
- SettingsAccountTab.vue: new component with all AccountView content (2FA, password, sessions)
- SettingsView.vue: add Account tab rendering SettingsAccountTab; import SettingsAccountTab

frontend/package.json

@@ -10,6 +10,7 @@
   },
   "dependencies": {
     "pinia": "^2.1.0",
+    "qrcode": "^1.5.4",
     "vue": "^3.4.0",
     "vue-router": "^4.3.0"
   },

frontend/src/components/auth/TotpEnrollment.vue

@@ -28,17 +28,10 @@
             Open your authenticator app and scan this QR code, or enter the key manually.
           </p>
 
-          <!-- QR code — rendered via provisioning URI link (no QR library dependency) -->
+          <!-- QR code — rendered as an inline image via qrcode library -->
           <div class="bg-white border border-gray-200 rounded-xl p-6 flex flex-col items-center gap-4">
-            <p class="text-xs text-gray-500 text-center">Scan with your authenticator app using the link below, or enter the secret key manually:</p>
-            <a
-              :href="qrUri"
-              class="text-sm font-semibold text-indigo-600 hover:text-indigo-700 underline break-all text-center"
-              target="_blank"
-              rel="noopener noreferrer"
-            >
-              Open in authenticator app
-            </a>
+            <p class="text-xs text-gray-500 text-center">Scan this QR code with your authenticator app:</p>
+            <img v-if="qrDataUrl" :src="qrDataUrl" alt="TOTP QR code" class="w-48 h-48 rounded-xl border border-gray-200" />
           </div>
         </div>
 
@@ -115,6 +108,7 @@
 
 <script setup>
 import { ref } from 'vue'
+import QRCode from 'qrcode'
 import * as api from '../../api/client.js'
 import AppSpinner from '../ui/AppSpinner.vue'
 import BackupCodesDisplay from './BackupCodesDisplay.vue'
@@ -123,6 +117,7 @@ const emit = defineEmits(['enrolled'])
 
 const step = ref('setup')
 const qrUri = ref('')
+const qrDataUrl = ref('')
 const secret = ref('')
 const verifyCode = ref('')
 const backupCodes = ref([])
@@ -138,6 +133,7 @@ async function startSetup() {
     const data = await api.totpSetup()
     qrUri.value = data.provisioning_uri
     secret.value = data.secret
+    qrDataUrl.value = await QRCode.toDataURL(qrUri.value, { width: 200, margin: 1 })
     step.value = 'verify'
   } catch (e) {
     error.value = e.message

frontend/src/components/settings/SettingsAccountTab.vue

@@ -0,0 +1,253 @@
+<template>
+  <div class="space-y-6">
+
+    <!-- 1. Account information -->
+    <section class="bg-white border border-gray-200 rounded-xl p-6">
+      <h3 class="font-semibold text-gray-800 mb-4">Account information</h3>
+      <div class="space-y-2 text-sm text-gray-700">
+        <div><span class="text-gray-500">Email:</span> {{ authStore.user?.email }}</div>
+        <div><span class="text-gray-500">Username:</span> @{{ authStore.user?.handle }}</div>
+        <div class="flex items-center gap-2">
+          <span class="text-gray-500">Role:</span>
+          <span
+            class="inline-flex items-center px-2 py-1 rounded text-xs font-semibold"
+            :class="authStore.user?.role === 'admin'
+              ? 'bg-indigo-100 text-indigo-700'
+              : 'bg-gray-100 text-gray-600'"
+          >
+            {{ authStore.user?.role }}
+          </span>
+        </div>
+      </div>
+    </section>
+
+    <!-- 2. Two-factor authentication -->
+    <section class="bg-white border border-gray-200 rounded-xl p-6">
+      <h3 class="font-semibold text-gray-800 mb-4">Two-factor authentication</h3>
+
+      <!-- TOTP enabled: show status + disable option -->
+      <template v-if="authStore.user?.totp_enabled">
+        <div class="flex items-center gap-3 mb-4">
+          <span class="inline-flex items-center gap-1.5 text-sm text-green-700 font-semibold">
+            <!-- Checkmark -->
+            <svg class="w-4 h-4" xmlns="http://www.w3.org/2000/svg" fill="none" viewBox="0 0 24 24" stroke-width="2" stroke="currentColor">
+              <path stroke-linecap="round" stroke-linejoin="round" d="M4.5 12.75l6 6 9-13.5" />
+            </svg>
+            Enabled
+          </span>
+        </div>
+
+        <template v-if="!confirmDisable2fa">
+          <button
+            type="button"
+            @click="confirmDisable2fa = true"
+            class="text-sm px-4 py-2 border border-red-300 text-red-600 rounded-lg hover:bg-red-50 transition-colors"
+          >
+            Disable 2FA
+          </button>
+        </template>
+        <template v-else>
+          <ConfirmBlock
+            message="This will disable two-factor authentication. Your account will be less secure."
+            confirm-label="Disable 2FA"
+            cancel-label="Keep enabled"
+            @confirmed="disableTotp"
+            @cancelled="confirmDisable2fa = false"
+          />
+          <p v-if="totpError" class="mt-2 text-xs text-red-600">{{ totpError }}</p>
+        </template>
+      </template>
+
+      <!-- TOTP not enabled: show enrollment component -->
+      <template v-else>
+        <TotpEnrollment @enrolled="onTotpEnrolled" />
+      </template>
+    </section>
+
+    <!-- 3. Change password -->
+    <section class="bg-white border border-gray-200 rounded-xl p-6">
+      <h3 class="font-semibold text-gray-800 mb-4">Change password</h3>
+
+      <form @submit.prevent="changePassword" class="space-y-4 max-w-sm">
+        <div>
+          <label class="block text-sm font-semibold text-gray-700 mb-1">Current password</label>
+          <input
+            v-model="currentPassword"
+            type="password"
+            required
+            autocomplete="current-password"
+            class="block w-full rounded-lg px-3 py-3 text-sm border bg-white text-gray-900 transition-colors focus:ring-2 focus:outline-none"
+            :class="passwordError && passwordError.includes('Current')
+              ? 'border-red-500 focus:ring-red-500 focus:border-red-500'
+              : 'border-gray-300 focus:ring-indigo-500 focus:border-indigo-500'"
+          />
+          <p
+            v-if="passwordError && passwordError.includes('Current')"
+            class="mt-1 text-xs text-red-600"
+          >
+            {{ passwordError }}
+          </p>
+        </div>
+
+        <div>
+          <label class="block text-sm font-semibold text-gray-700 mb-1">New password</label>
+          <input
+            v-model="newPassword"
+            type="password"
+            required
+            autocomplete="new-password"
+            class="block w-full rounded-lg px-3 py-3 text-sm border bg-white text-gray-900 transition-colors focus:ring-2 focus:outline-none"
+            :class="passwordError && !passwordError.includes('Current')
+              ? 'border-red-500 focus:ring-red-500 focus:border-red-500'
+              : 'border-gray-300 focus:ring-indigo-500 focus:border-indigo-500'"
+          />
+          <PasswordStrengthBar :password="newPassword" />
+        </div>
+
+        <!-- Form-level error (e.g. breach check, strength failure) -->
+        <div
+          v-if="passwordError && !passwordError.includes('Current')"
+          class="p-3 rounded-lg bg-red-50 border border-red-200 text-sm text-red-700"
+        >
+          {{ passwordError }}
+        </div>
+
+        <div v-if="passwordSuccess" class="text-sm text-green-600">{{ passwordSuccess }}</div>
+
+        <button
+          type="submit"
+          :disabled="changingPassword"
+          class="flex items-center gap-2 px-6 py-2.5 bg-indigo-600 text-white rounded-lg text-sm font-semibold hover:bg-indigo-700 transition-colors disabled:opacity-75 min-h-[44px]"
+        >
+          <AppSpinner v-if="changingPassword" />
+          {{ changingPassword ? 'Updating…' : 'Update password' }}
+        </button>
+      </form>
+    </section>
+
+    <!-- 4. Sessions — sign out all devices -->
+    <section class="bg-white border border-gray-200 rounded-xl p-6">
+      <h3 class="font-semibold text-gray-800 mb-4">Sessions</h3>
+
+      <template v-if="!confirmSignOutAll">
+        <button
+          type="button"
+          @click="confirmSignOutAll = true"
+          class="text-sm px-4 py-2 border border-red-300 text-red-600 rounded-lg hover:bg-red-50 transition-colors"
+        >
+          Sign out all devices
+        </button>
+      </template>
+
+      <template v-else>
+        <ConfirmBlock
+          message="This will sign you out of all devices, including this one. You will need to sign in again."
+          confirm-label="Sign out all devices"
+          cancel-label="Keep signed in"
+          @confirmed="signOutAll"
+          @cancelled="confirmSignOutAll = false"
+        >
+          <template #confirm-button>
+            <button
+              type="button"
+              @click="signOutAll"
+              :disabled="signingOutAll"
+              class="flex items-center gap-2 px-4 py-2 bg-red-600 hover:bg-red-700 text-white text-sm font-semibold rounded-lg disabled:opacity-75 min-h-[44px]"
+            >
+              <AppSpinner v-if="signingOutAll" />
+              Sign out all devices
+            </button>
+          </template>
+        </ConfirmBlock>
+      </template>
+    </section>
+
+  </div>
+</template>
+
+<script setup>
+import { ref } from 'vue'
+import { useRouter } from 'vue-router'
+import { useAuthStore } from '../../stores/auth.js'
+import * as api from '../../api/client.js'
+import PasswordStrengthBar from '../auth/PasswordStrengthBar.vue'
+import TotpEnrollment from '../auth/TotpEnrollment.vue'
+import ConfirmBlock from '../ui/ConfirmBlock.vue'
+import AppSpinner from '../ui/AppSpinner.vue'
+
+const authStore = useAuthStore()
+const router = useRouter()
+
+// ── Change password ─────────────────────────────────────────────────────────
+
+const currentPassword = ref('')
+const newPassword = ref('')
+const changingPassword = ref(false)
+const passwordError = ref(null)
+const passwordSuccess = ref(null)
+
+async function changePassword() {
+  changingPassword.value = true
+  passwordError.value = null
+  passwordSuccess.value = null
+  try {
+    await api.changePassword({
+      current_password: currentPassword.value,
+      new_password: newPassword.value,
+    })
+    passwordSuccess.value = 'Password updated.'
+    currentPassword.value = ''
+    newPassword.value = ''
+  } catch (e) {
+    const msg = e.message || ''
+    if (msg.toLowerCase().includes('current') || msg.toLowerCase().includes('incorrect')) {
+      passwordError.value = 'Current password is incorrect'
+    } else if (msg.toLowerCase().includes('breach')) {
+      passwordError.value = 'This password has appeared in a data breach. Choose a different password.'
+    } else {
+      passwordError.value = msg
+    }
+  } finally {
+    changingPassword.value = false
+  }
+}
+
+// ── TOTP enrollment ─────────────────────────────────────────────────────────
+
+const confirmDisable2fa = ref(false)
+const totpError = ref(null)
+
+function onTotpEnrolled() {
+  if (authStore.user) {
+    authStore.user.totp_enabled = true
+  }
+}
+
+async function disableTotp() {
+  totpError.value = null
+  try {
+    await api.totpDisable()
+    if (authStore.user) {
+      authStore.user.totp_enabled = false
+    }
+    confirmDisable2fa.value = false
+  } catch (e) {
+    totpError.value = e.message
+  }
+}
+
+// ── Sign out all devices ────────────────────────────────────────────────────
+
+const confirmSignOutAll = ref(false)
+const signingOutAll = ref(false)
+
+async function signOutAll() {
+  signingOutAll.value = true
+  try {
+    await authStore.logoutAll()
+    await router.push('/login')
+  } finally {
+    signingOutAll.value = false
+  }
+}
+</script>

frontend/src/views/SettingsView.vue

@@ -48,6 +48,9 @@
     <!-- Tab: AI Configuration -->
     <SettingsAiTab v-if="activeTab === 'ai'" />
 
+    <!-- Tab: Account -->
+    <SettingsAccountTab v-if="activeTab === 'account'" />
+
     <!-- Tab: Cloud Storage -->
     <div v-if="activeTab === 'cloud'">
       <!-- OAuth error banner (persistent until dismissed) -->
@@ -86,6 +89,7 @@ import { useRouter } from 'vue-router'
 import SettingsPreferencesTab from '../components/settings/SettingsPreferencesTab.vue'
 import SettingsAiTab from '../components/settings/SettingsAiTab.vue'
 import SettingsCloudTab from '../components/settings/SettingsCloudTab.vue'
+import SettingsAccountTab from '../components/settings/SettingsAccountTab.vue'
 
 const router = useRouter()
 
@@ -93,6 +97,7 @@ const tabs = [
   { id: 'preferences', label: 'Preferences' },
   { id: 'ai', label: 'AI Configuration' },
   { id: 'cloud', label: 'Cloud Storage' },
+  { id: 'account', label: 'Account' },
 ]
 
 const activeTab = ref('preferences')