fix(concord): sweep the stock relays for Direct Invites too

A sender that finds no kind-10050 or NIP-65 list for us delivers a Direct
Invite to the stock Concord set (CORD-05 §6). We swept only our own DM relays
whenever any were configured, so those invites never arrived; Armada's to an
account with no published relay lists was one. Sweep both.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

commons/src/commonMain/kotlin/com/vitorpamplona/amethyst/commons/model/AccountConcordActions.kt

@@ -931,12 +931,14 @@ class AccountConcordActions(
     /**
      * Where this account scans for Direct Invites — where senders deliver them (CORD-05 §6): our DM
      * inbox relays (kind 10050, plus the NIP-65 read and private/local relays the DM feed already
-     * reads), else the stock Concord set.
+     * reads), plus the stock Concord set.
      */
     private fun concordDirectInviteScanRelays(): Set<NormalizedRelayUrl> =
-        account.dmRelays.flow.value.ifEmpty {
-            ConcordActions.directInviteDeliveryRelays(null)
-        }
+        // Our inbox relays AND the stock set, always: a sender that could not find our relay lists
+        // (none published, or none reachable) delivers to the stock set (CORD-05 §6), and we can't
+        // know which case a sender hit. Sweeping only our DM relays missed every invite from such a
+        // sender; Armada's to an account with no published kind 10050 never arrived.
+        account.dmRelays.flow.value + ConcordActions.directInviteDeliveryRelays(null)
 
     /**
      * Sweeps our inbox relays for Direct Invite wraps