fix(account): always include broadcasting relays in non-private sends

The ShortNotePost compose path went through
`signAndComputeBroadcast` → `computeRelayListToBroadcast(event)`, which
only mixed in the user's broadcasting relays indirectly via
`outboxRelays` — and only when `author == userProfile()`. Two real
paths dropped the broadcast list entirely:

  * Anonymous posts (`signAnonymouslyAndBroadcast`) sign with a
    throwaway pubkey, so `author != userProfile()` and the branch that
    pulls in `outboxRelays.flow.value` is skipped.
  * `MetadataEvent` / `AdvertisedRelayListEvent` returned early with
    `followPlusAllMineWithIndex + availableRelays`, neither of which
    includes the broadcast list.

Hoist `broadcastRelayList.flow.value` to the top of the function (after
the `GiftWrapEvent` / `WrappedEvent` early returns that defines what
"private" means) and seed it into every non-private return path. Sets
dedupe so the regular path stays unchanged in the common case where
broadcasting relays were already reachable through `outboxRelays`.

amethyst/src/main/java/com/vitorpamplona/amethyst/model/Account.kt

@@ -937,10 +937,6 @@ class Account(
     private fun computeRelaysForChannels(event: Event): Set<NormalizedRelayUrl> = cache.getAnyChannel(event)?.relays() ?: emptySet()
 
     fun computeRelayListToBroadcast(event: Event): Set<NormalizedRelayUrl> {
-        if (event is MetadataEvent || event is AdvertisedRelayListEvent) {
-            // everywhere
-            return followPlusAllMineWithIndex.flow.value + client.availableRelaysFlow().value
-        }
         if (event is GiftWrapEvent) {
             val receiver = event.recipientPubKey()
             if (receiver != null) {
@@ -959,7 +955,16 @@ class Account(
             return emptySet()
         }
 
+        // Non-private sends always go to the user's broadcasting relays.
+        val broadcastRelays = broadcastRelayList.flow.value
+
+        if (event is MetadataEvent || event is AdvertisedRelayListEvent) {
+            // everywhere
+            return followPlusAllMineWithIndex.flow.value + client.availableRelaysFlow().value + broadcastRelays
+        }
+
         val relayList = mutableSetOf<NormalizedRelayUrl>()
+        relayList.addAll(broadcastRelays)
 
         val author = cache.getUserIfExists(event.pubKey)