feat: factory reset, backup restore, auto-identity creation

- system.factory-reset RPC: wipes user data, preserves images/node_key
- Factory Reset button in Settings with confirmation modal
- backup.restore-identity RPC: decrypts and restores DID key
- Restore from Backup panel in OnboardingIntro first screen
- Auto-create default identity with Nostr key on boot if none exist

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

neode-ui/src/views/OnboardingIntro.vue

@@ -23,20 +23,103 @@
         >
           Unlock your sovereignty →
         </button>
+
+        <a
+          class="text-white/50 hover:text-white/80 underline text-sm cursor-pointer mt-4 block text-center onb-cta"
+          @click="showRestore = true"
+        >
+          Restore from backup
+        </a>
+
+        <!-- Restore Panel -->
+        <div v-if="showRestore" class="mt-6 glass-card px-6 py-6 text-left">
+          <h3 class="text-sm font-semibold text-white/80 mb-3 uppercase tracking-wide">Restore Identity from Backup</h3>
+          <input
+            type="file"
+            accept=".json"
+            class="block w-full text-sm text-white/60 file:mr-4 file:py-2 file:px-4 file:rounded file:border-0 file:text-sm file:bg-white/10 file:text-white/80 hover:file:bg-white/20 mb-3"
+            @change="onFileSelect"
+          />
+          <input
+            v-model="passphrase"
+            type="password"
+            placeholder="Backup passphrase"
+            class="w-full px-4 py-2 bg-white/10 border border-white/20 rounded-lg text-white text-sm focus:outline-none focus:border-white/40 mb-3"
+          />
+          <p v-if="restoreError" class="text-red-400 text-xs mb-2">{{ restoreError }}</p>
+          <p v-if="restoreSuccess" class="text-green-400 text-xs mb-2">Identity restored successfully!</p>
+          <div class="flex gap-3">
+            <button class="glass-button text-sm px-4 py-2" @click="showRestore = false">Cancel</button>
+            <button
+              class="glass-button text-sm px-4 py-2"
+              :disabled="!restoreFile || !passphrase || restoreLoading"
+              @click="performRestore"
+            >
+              {{ restoreLoading ? 'Restoring...' : 'Restore' }}
+            </button>
+          </div>
+        </div>
       </div>
     </div>
   </div>
 </template>
 
 <script setup lang="ts">
+import { ref } from 'vue'
 import { useRouter } from 'vue-router'
 import AnimatedLogo from '@/components/AnimatedLogo.vue'
+import { rpcClient } from '@/api/rpc-client'
 
 const router = useRouter()
 
 function goToOptions() {
   router.push('/onboarding/path').catch(() => {})
 }
+
+// Restore from backup
+const showRestore = ref(false)
+const restoreFile = ref<Record<string, unknown> | null>(null)
+const passphrase = ref('')
+const restoreLoading = ref(false)
+const restoreError = ref('')
+const restoreSuccess = ref(false)
+
+function onFileSelect(e: Event) {
+  const target = e.target as HTMLInputElement
+  const file = target.files?.[0]
+  if (!file) return
+  const reader = new FileReader()
+  reader.onload = () => {
+    try {
+      restoreFile.value = JSON.parse(reader.result as string)
+      restoreError.value = ''
+    } catch {
+      restoreError.value = 'Invalid backup file format'
+      restoreFile.value = null
+    }
+  }
+  reader.readAsText(file)
+}
+
+async function performRestore() {
+  if (!restoreFile.value || !passphrase.value) return
+  restoreLoading.value = true
+  restoreError.value = ''
+  try {
+    await rpcClient.call({
+      method: 'backup.restore-identity',
+      params: { backup: restoreFile.value, passphrase: passphrase.value },
+    })
+    restoreSuccess.value = true
+    setTimeout(() => {
+      router.push('/onboarding/did')
+    }, 1500)
+  } catch (err) {
+    restoreError.value = err instanceof Error ? err.message : 'Restore failed'
+  } finally {
+    restoreLoading.value = false
+  }
+}
 </script>
 
 <style scoped>

neode-ui/src/views/Settings.vue

@@ -818,6 +818,42 @@
         </button>
       </div>
     </div>
+
+    <!-- Factory Reset Section -->
+    <div class="path-option-card px-6 py-6 mt-6 border-red-500/30">
+      <h2 class="text-xl font-semibold text-red-400/90 mb-3">Factory Reset</h2>
+      <p class="text-sm text-white/60 mb-4">
+        Wipe all user data, identities, and credentials. Container images are preserved. The node will restart and show the onboarding screen.
+      </p>
+      <button
+        class="glass-button text-red-400 border-red-500/30 hover:border-red-500/50"
+        @click="showFactoryResetConfirm = true"
+      >
+        Factory Reset
+      </button>
+    </div>
+
+    <!-- Factory Reset Confirmation Modal -->
+    <Teleport to="body">
+      <div v-if="showFactoryResetConfirm" class="fixed inset-0 z-50 flex items-center justify-center bg-black/60 backdrop-blur-sm">
+        <div class="glass-card px-8 py-8 max-w-md mx-4">
+          <h3 class="text-lg font-semibold text-white/90 mb-3">Are you sure?</h3>
+          <p class="text-sm text-white/60 mb-6">
+            This will delete all identities, credentials, and settings. This cannot be undone.
+          </p>
+          <div class="flex gap-3 justify-end">
+            <button class="glass-button" @click="showFactoryResetConfirm = false">Cancel</button>
+            <button
+              class="glass-button text-red-400 border-red-500/30"
+              :disabled="factoryResetLoading"
+              @click="performFactoryReset"
+            >
+              {{ factoryResetLoading ? 'Resetting...' : 'Yes, Reset' }}
+            </button>
+          </div>
+        </div>
+      </div>
+    </Teleport>
   </div>
 </template>
 
@@ -837,6 +873,24 @@ import type { UIMode } from '@/types/api'
 const router = useRouter()
 const { t, locale } = useI18n()
 const store = useAppStore()
+
+// Factory Reset
+const showFactoryResetConfirm = ref(false)
+const factoryResetLoading = ref(false)
+async function performFactoryReset() {
+  factoryResetLoading.value = true
+  try {
+    await rpcClient.call({ method: 'system.factory-reset', params: { confirm: true } })
+    localStorage.clear()
+    showFactoryResetConfirm.value = false
+    router.push('/onboarding/intro')
+  } catch (err) {
+    // Service likely restarted — redirect anyway
+    localStorage.clear()
+    showFactoryResetConfirm.value = false
+    router.push('/onboarding/intro')
+  }
+}
 const supportedLocales = SUPPORTED_LOCALES
 const currentLocale = computed(() => locale.value)
 async function changeLocale(code: string) {