refactor(quartz): NIP-86 bans purge matching events via onBan(filter) hook

Nip86Server used to take an optional IEventStore and call store.delete()
only on banevent — banpubkey and disallowkind would update the BanStore
but leave existing matching events served by REQ. That's inconsistent
(an operator who bans a spam pubkey expects the spam to be gone) and
a real safety issue (banning a CSAM event wouldn't actually remove
existing copies if the store was null).

Replace the IEventStore param with onBan: suspend (Filter) -> Unit. The
dispatcher fires it after each ban method with the Filter that selects
the now-banned events:
  banpubkey   → Filter(authors = [pk])
  banevent    → Filter(ids = [id])
  disallowkind→ Filter(kinds = [k])

KtorRelay wires onBan = { f -> relay.store.delete(f) }, so the existing
SQLite delete-by-filter path handles every shape without the caller
having to know which field to populate. The default no-op keeps the
unit test for the dispatcher dependency-free.

withInt is now suspend so disallowKind's handler can call the suspending
onBan inline.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

geode/src/main/kotlin/com/vitorpamplona/geode/KtorRelay.kt

@@ -113,7 +113,12 @@ class KtorRelay(
             }
         }
 
-    private val nip86Server = Nip86Server(banStore = relay.banStore, infoHolder = infoHolder, store = relay.store)
+    private val nip86Server =
+        Nip86Server(
+            banStore = relay.banStore,
+            infoHolder = infoHolder,
+            onBan = { filter -> relay.store.delete(filter) },
+        )
     private val nip86Route =
         Nip86HttpRoute(
             server = nip86Server,