fix(ui): sanitize WireGuard QR SVG, guard mesh poll interval, log catalog fetch failures

Server.vue rendered the backend-generated WireGuard peer QR with raw
v-html while the analogous TOTP QR was DOMPurify-sanitized — both now
use the same svg-profile sanitizer. Mesh.vue's 5s poll interval gets
the same start-guard as the arch poll (no leak on double-mount) and is
nulled on unmount. curatedApps.ts catalog fetches no longer fail
silently: each failed source logs a console.warn, including the final
all-sources-failed fallback to the hardcoded list.

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

neode-ui/src/views/Mesh.vue

@@ -388,13 +388,15 @@ onMounted(async () => {
   if (!archPollInterval) {
     archPollInterval = setInterval(loadArchMessages, 15000)
   }
-  pollInterval = setInterval(() => {
-    mesh.fetchStatus()
-    mesh.fetchPeers()
-    mesh.fetchMessages()
-    mesh.fetchDeadmanStatus()
-    mesh.fetchBlockHeaders()
-  }, 5000)
+  if (!pollInterval) {
+    pollInterval = setInterval(() => {
+      mesh.fetchStatus()
+      mesh.fetchPeers()
+      mesh.fetchMessages()
+      mesh.fetchDeadmanStatus()
+      mesh.fetchBlockHeaders()
+    }, 5000)
+  }
 
   // Instant peer updates (#48): the backend nudges the data-model revision when
   // it discovers/updates a mesh peer, so refetch peers on the WS push rather
@@ -414,7 +416,7 @@ onUnmounted(() => {
     window.visualViewport.removeEventListener('scroll', updateKeyboardInset)
   }
   document.documentElement.style.removeProperty('--keyboard-inset')
-  if (pollInterval) clearInterval(pollInterval)
+  if (pollInterval) { clearInterval(pollInterval); pollInterval = null }
   if (archPollInterval) { clearInterval(archPollInterval); archPollInterval = null }
   if (wsUnsub) { wsUnsub(); wsUnsub = null }
 })

neode-ui/src/views/Server.vue

@@ -306,7 +306,7 @@
             </div>
             <!-- Existing peer QR view -->
             <div v-else-if="peerQrData && !showingNewDevice" class="text-center">
-              <div class="bg-white rounded-xl p-4 mb-4 inline-block" v-html="peerQrData.qr_svg"></div>
+              <div class="bg-white rounded-xl p-4 mb-4 inline-block" v-html="sanitizedPeerQrSvg"></div>
               <p class="text-sm text-white/70 mb-2">Scan with the <strong>WireGuard</strong> app</p>
               <p class="text-xs text-white/40 font-mono mb-4">{{ peerQrData.peer_ip }}</p>
               <div class="flex gap-2">
@@ -318,7 +318,7 @@
             <div v-else>
               <div v-if="peerQrData">
                 <div class="text-center">
-                  <div class="bg-white rounded-xl p-4 mb-4 inline-block" v-html="peerQrData.qr_svg"></div>
+                  <div class="bg-white rounded-xl p-4 mb-4 inline-block" v-html="sanitizedPeerQrSvg"></div>
                   <p class="text-sm text-white/70 mb-2">Scan with the <strong>WireGuard</strong> app</p>
                   <p class="text-xs text-white/40 font-mono mb-4">{{ peerQrData.peer_ip }}</p>
                   <div class="flex gap-2">
@@ -406,6 +406,7 @@
 
 <script setup lang="ts">
 import { ref, computed, onMounted, onUnmounted, watch } from 'vue'
+import DOMPurify from 'dompurify'
 import { rpcClient } from '@/api/rpc-client'
 import { useAppStore } from '@/stores/app'
 import QuickActionsCard from './server/QuickActionsCard.vue'
@@ -499,6 +500,11 @@ const showAddDeviceModal = ref(false)
 const newPeerName = ref('')
 const creatingPeer = ref(false)
 const peerQrData = ref<{ qr_svg: string; config: string; peer_ip: string } | null>(null)
+// Sanitize like TwoFactorSection's TOTP QR — the SVG is backend-generated,
+// but v-html without a sanitizer is one compromised RPC away from XSS.
+const sanitizedPeerQrSvg = computed(() =>
+  DOMPurify.sanitize(peerQrData.value?.qr_svg ?? '', { USE_PROFILES: { svg: true } }),
+)
 const peerError = ref('')
 const copiedConfig = ref(false)
 const vpnPeers = ref<{ name: string; ip: string; type?: string; npub?: string }[]>([])

neode-ui/src/views/discover/curatedApps.ts

@@ -57,7 +57,10 @@ export async function fetchAppCatalog(): Promise<AppCatalog | null> {
       // Cache in localStorage for offline fallback
       try { localStorage.setItem('archy_catalog', JSON.stringify(data)) } catch {}
       return data
-    } catch { continue }
+    } catch (e) {
+      console.warn(`[catalog] fetch failed for ${url}:`, e)
+      continue
+    }
   }
 
   // Try localStorage cache as final fallback
@@ -68,8 +71,11 @@ export async function fetchAppCatalog(): Promise<AppCatalog | null> {
       catalogFetchedAt = Date.now() - CATALOG_TTL + 5 * 60 * 1000 // re-check in 5 min
       return cachedCatalog
     }
-  } catch {}
+  } catch (e) {
+    console.warn('[catalog] localStorage fallback unreadable:', e)
+  }
 
+  console.warn('[catalog] all sources failed — using hardcoded app list')
   return null
 }