feat: Nostr profile enrichment with caching

Fetch full kind:0 metadata (display_name, about, banner, nip05) from
relays with a 5-min TTL cache. Show Nostr banner, display name, and
NIP-05 on bot profile pages. Expose ownerPubkey in stats API.

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

frontend/src/composables/useNostr.ts

@@ -397,21 +397,46 @@ export function useNostr() {
     updateWebhook,
     getStoredNsec,
     logout,
+    fetchNostrProfile,
   }
 }
 
+export interface NostrProfile {
+  displayName: string | null
+  about: string | null
+  picture: string | null
+  banner: string | null
+  nip05: string | null
+}
+
+// Profile cache with 5-min TTL
+const profileCache = new Map<string, { data: NostrProfile; ts: number }>()
+const PROFILE_TTL = 5 * 60 * 1000
+
+const RELAYS = [
+  'wss://relay.damus.io',
+  'wss://relay.nostr.band',
+  'wss://nos.lol',
+]
+
 // Fetch profile picture from a Nostr relay
 async function fetchNostrProfilePic(pk: string): Promise<string | null> {
-  const relays = [
-    'wss://relay.damus.io',
-    'wss://relay.nostr.band',
-    'wss://nos.lol',
-  ]
+  const profile = await fetchNostrProfile(pk)
+  return profile?.picture || null
+}
 
-  for (const relay of relays) {
+/** Fetch full Nostr profile (kind:0 metadata) with caching */
+async function fetchNostrProfile(pk: string): Promise<NostrProfile | null> {
+  const cached = profileCache.get(pk)
+  if (cached && Date.now() - cached.ts < PROFILE_TTL) return cached.data
+
+  for (const relay of RELAYS) {
     try {
-      const pic = await queryRelay(relay, pk)
-      if (pic) return pic
+      const profile = await queryRelayProfile(relay, pk)
+      if (profile) {
+        profileCache.set(pk, { data: profile, ts: Date.now() })
+        return profile
+      }
     } catch {
       continue
     }
@@ -419,7 +444,7 @@ async function fetchNostrProfilePic(pk: string): Promise<string | null> {
   return null
 }
 
-function queryRelay(url: string, pk: string): Promise<string | null> {
+function queryRelayProfile(url: string, pk: string): Promise<NostrProfile | null> {
   return new Promise((resolve) => {
     let timedOut = false
     const timeout = setTimeout(() => {
@@ -433,7 +458,6 @@ function queryRelay(url: string, pk: string): Promise<string | null> {
 
     ws.onopen = () => {
       if (timedOut) { ws.close(); return }
-      // Request kind 0 (metadata) for this pubkey
       ws.send(JSON.stringify(['REQ', subId, { kinds: [0], authors: [pk], limit: 1 }]))
     }
 
@@ -444,7 +468,13 @@ function queryRelay(url: string, pk: string): Promise<string | null> {
           const meta = JSON.parse(data[2].content)
           clearTimeout(timeout)
           ws.close()
-          resolve(meta.picture || null)
+          resolve({
+            displayName: meta.display_name || meta.name || null,
+            about: meta.about || null,
+            picture: meta.picture || null,
+            banner: meta.banner || null,
+            nip05: meta.nip05 || null,
+          })
         } else if (data[0] === 'EOSE') {
           clearTimeout(timeout)
           ws.close()