feat(nostr): publish notes with per-relay status (M11.1)

Compose panel in Nostr tab, sign via NIP-07, broadcast to configured
relays with per-relay send status. Character counter (soft 280 limit).
Removed isDark conditionals from NostrGrid (dark-only app).

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

packages/app/src/composables/useNostr.ts

@@ -175,6 +175,57 @@ function disconnect() {
   initialized = false
 }
 
+export interface PublishResult {
+  url: string
+  success: boolean
+  message: string
+}
+
+function publishEvent(signedEvent: NostrEvent): Promise<PublishResult[]> {
+  const connectedRelays = relays.filter(r => r.connected && r.ws)
+  if (connectedRelays.length === 0) {
+    return Promise.resolve([])
+  }
+
+  const results = connectedRelays.map(relay => {
+    return new Promise<PublishResult>((resolve) => {
+      const timer = setTimeout(() => {
+        resolve({ url: relay.url, success: false, message: 'Timeout' })
+      }, 5000)
+
+      const handler = (msg: MessageEvent) => {
+        try {
+          const data = JSON.parse(msg.data)
+          // NIP-01: ["OK", <event_id>, <accepted>, <message>]
+          if (Array.isArray(data) && data[0] === 'OK' && data[1] === signedEvent.id) {
+            clearTimeout(timer)
+            relay.ws?.removeEventListener('message', handler)
+            resolve({
+              url: relay.url,
+              success: !!data[2],
+              message: data[3] ?? (data[2] ? 'Published' : 'Rejected'),
+            })
+          }
+        } catch { /* skip */ }
+      }
+
+      relay.ws!.addEventListener('message', handler)
+      try {
+        relay.ws!.send(JSON.stringify(['EVENT', signedEvent]))
+      } catch {
+        clearTimeout(timer)
+        relay.ws?.removeEventListener('message', handler)
+        resolve({ url: relay.url, success: false, message: 'Send failed' })
+      }
+    })
+  })
+
+  // Also add to our local feed
+  addEvent(signedEvent)
+
+  return Promise.all(results)
+}
+
 function fetchNote(hexId: string, timeoutMs = 5000): Promise<NostrNote | null> {
   // Check if already cached
   const cached = events.value.find(e => e.id === hexId)
@@ -237,5 +288,6 @@ export function useNostr() {
     connect,
     disconnect,
     fetchNote,
+    publishEvent,
   }
 }