feat(nostr): NIP-05 verification badge with 24h cache (M11.6)

Verify NIP-05 identifiers by fetching .well-known/nostr.json from
the domain. Results cached in localStorage for 24 hours. Green
checkmark badge shown next to verified NIP-05 on note cards.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

packages/app/src/components/content/NostrGrid.vue

@@ -143,7 +143,16 @@
               <span class="text-xs font-semibold truncate text-white/80">
                 {{ note.authorName ?? 'anon' }}
               </span>
-              <span v-if="note.nip05" class="text-[9px] truncate text-purple-400/60">
+              <span v-if="note.nip05" class="text-[9px] truncate text-purple-400/60 flex items-center gap-0.5">
+                <svg
+                  v-if="nip05Status[note.id] === true"
+                  class="w-2.5 h-2.5 text-emerald-400 shrink-0"
+                  fill="currentColor"
+                  viewBox="0 0 20 20"
+                  :title="note.nip05"
+                >
+                  <path fill-rule="evenodd" d="M16.707 5.293a1 1 0 010 1.414l-8 8a1 1 0 01-1.414 0l-4-4a1 1 0 011.414-1.414L8 12.586l7.293-7.293a1 1 0 011.414 0z" clip-rule="evenodd" />
+                </svg>
                 {{ note.nip05 }}
               </span>
               <span class="text-[9px] ml-auto shrink-0 text-white/20">
@@ -209,11 +218,12 @@
 </template>
 
 <script setup lang="ts">
-import { ref, computed, onMounted, nextTick } from 'vue'
+import { ref, computed, reactive, onMounted, nextTick, watch } from 'vue'
 import NostrDMs from './NostrDMs.vue'
 import NostrRelayManager from './NostrRelayManager.vue'
 import NostrProfileEditor from './NostrProfileEditor.vue'
 import ZapDialog from './ZapDialog.vue'
+import { useNip05Verification } from '@/composables/useNip05Verification'
 import { useNostr, type NostrNote, type PublishResult } from '@/composables/useNostr'
 import { useNostrIdentity } from '@/composables/useNostrIdentity'
 
@@ -221,6 +231,7 @@ defineEmits<{ selectNote: [note: NostrNote] }>()
 
 const { events: notes, isConnected, relayStates, connect, publishEvent } = useNostr()
 const { isLoggedIn, signEvent } = useNostrIdentity()
+const { verifyNip05 } = useNip05Verification()
 
 const activeSubTab = ref<'feed' | 'dms' | 'relays' | 'profile'>('feed')
 const subTabs = [
@@ -249,6 +260,8 @@ function openZap(note: NostrNote) {
   zapOpen.value = true
 }
 
+const nip05Status = reactive<Record<string, boolean | null>>({})
+
 const noteKinds = [
   { id: 1, label: 'Notes' },
   { id: 30023, label: 'Articles' },
@@ -280,6 +293,18 @@ const filteredNotes = computed(() => {
   return result
 })
 
+// Verify NIP-05 for notes that have it
+watch(filteredNotes, (visibleNotes) => {
+  for (const note of visibleNotes) {
+    if (note.nip05 && nip05Status[note.id] === undefined) {
+      nip05Status[note.id] = null
+      verifyNip05(note.nip05, note.pubkey).then(result => {
+        nip05Status[note.id] = result
+      })
+    }
+  }
+}, { immediate: true })
+
 async function publishNote() {
   if (!composeText.value.trim() || isPublishing.value) return