Fix stale relay list: replace UserDefaults hex lookup with ndb query

Replace the fragile `latestRelayListEventIdHex` UserDefaults lookup in
`getLatestNIP65RelayListEvent()` with a direct nostrdb query using
`ndb.query(filters:maxResults:)` on the AUTHOR_KINDS index. This
eliminates the stale-hex failure mode where relay add/remove operations
would silently fall back to bootstrap or year-old relay lists.

Add an in-memory `lastSetRelayList` cache to bridge the nostrdb async
write gap — `set()` populates it, `getUserCurrentRelayList()` checks it
first, and `load()` clears it once ndb has committed.

Remove `latestRelayListEventIdHex` from: Delegate protocol,
DamusState, SaveKeysView, UserSettingsStore, and all test mocks.

Includes 5 regression tests that fail before the fix and pass after:
- testRemoveRelayDoesNotFallBackToBootstrapList
- testCacheBridgesAsyncWriteGap
- testRapidSequentialRemovesDoNotReintroduceRelays
- testLoadClearsCacheAndReadsFromNdb
- testNdbQueryFindsRelayListWithoutStoredHex

Changelog-Fixed: Fix stale relay list causing inability to disconnect relays
Closes: #3537
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
Signed-off-by: alltheseas <alltheseas@users.noreply.github.com>

damus/Core/Networking/NostrNetworkManager/NostrNetworkManager.swift

@@ -304,10 +304,7 @@ extension NostrNetworkManager {
         
         /// The keypair to use for relay authentication and updating relay lists
         var keypair: Keypair { get }
-        
-        /// The latest relay list event id hex
-        var latestRelayListEventIdHex: String? { get set }  // TODO: Update this once we have full NostrDB query support
-        
+
         /// The latest contact list `NostrEvent`
         ///
         /// Note: Read-only access, because `NostrNetworkManager` does not manage contact lists.

damus/Core/Networking/NostrNetworkManager/UserRelayListManager.swift

@@ -18,9 +18,14 @@ extension NostrNetworkManager {
         private var delegate: Delegate
         private let pool: RelayPool
         private let reader: SubscriptionManager
-        
+
         private var relayListObserverTask: Task<Void, Never>? = nil
         private var walletUpdatesObserverTask: AnyCancellable? = nil
+
+        /// In-memory cache of the most recently set relay list.
+        /// Bridges the gap between sending an event to nostrdb (async write) and it being queryable.
+        @MainActor
+        private var lastSetRelayList: NIP65.RelayList?
         
         init(delegate: Delegate, pool: RelayPool, reader: SubscriptionManager) {
             self.delegate = delegate
@@ -60,9 +65,11 @@ extension NostrNetworkManager {
         
         /// Gets the user's current relay list.
         ///
-        /// It attempts to get a NIP-65 relay list from the local database, or falls back to a legacy list.
+        /// It attempts to get the in-memory cache first (to bridge the nostrdb async write gap),
+        /// then a NIP-65 relay list from the local database, or falls back to a legacy list.
         @MainActor
         func getUserCurrentRelayList() -> NIP65.RelayList? {
+            if let lastSetRelayList { return lastSetRelayList }
             if let latestRelayListEvent = try? self.getLatestNIP65RelayList() { return latestRelayListEvent }
             if let latestRelayListEvent = try? self.getLatestKind3RelayList() { return latestRelayListEvent }
             if let latestRelayListEvent = try? self.getLatestUserDefaultsRelayList() { return latestRelayListEvent }
@@ -80,17 +87,18 @@ extension NostrNetworkManager {
             return list
         }
         
-        /// Gets the latest NIP-65 relay list event from NostrDB.
-        /// 
+        /// Gets the latest NIP-65 relay list event from NostrDB via query.
+        ///
         /// This is `private` because it is part of internal logic. Callers should use the higher level functions.
         ///
         /// It is recommended to use this function only if the NostrEvent metadata is needed. For cases where only the relay list info is needed, use `getLatestNIP65RelayList` instead.
         ///
         /// - Returns: The latest NIP-65 relay list NdbNote
         private func getLatestNIP65RelayListEvent() -> NdbNote? {
-            guard let latestRelayListEventId = delegate.latestRelayListEventIdHex else { return nil }
-            guard let latestRelayListEventId = NoteId(hex: latestRelayListEventId) else { return nil }
-            return try? delegate.ndb.lookup_note_and_copy(latestRelayListEventId)
+            let filter = NostrFilter(kinds: [.relay_list], limit: 1, authors: [delegate.keypair.pubkey])
+            guard let ndbFilter = try? NdbFilter(from: filter) else { return nil }
+            guard let noteKey = try? delegate.ndb.query(filters: [ndbFilter], maxResults: 1).first else { return nil }
+            return try? delegate.ndb.lookup_note_by_key_and_copy(noteKey)
         }
         
         /// Gets the latest `kind:3` relay list from NostrDB.
@@ -176,17 +184,19 @@ extension NostrNetworkManager {
         func set(userRelayList: NIP65.RelayList) async throws(UpdateError) {
             guard let fullKeypair = delegate.keypair.to_full() else { throw .notAuthorizedToChangeRelayList }
             guard let relayListEvent = userRelayList.toNostrEvent(keypair: fullKeypair) else { throw .cannotFormRelayListEvent }
-    
+
+            await MainActor.run { self.lastSetRelayList = userRelayList }
+
             await self.apply(newRelayList: self.computeRelaysToConnectTo(with: userRelayList))
-    
+
             await self.pool.send(.event(relayListEvent))   // This will send to NostrDB as well, which will locally save that NIP-65 event
-            self.delegate.latestRelayListEventIdHex = relayListEvent.id.hex()   // Make sure we are able to recall this event from NostrDB
         }
         
         // MARK: - Syncing our saved user relay list with the active `RelayPool`
         
         /// Loads the current user relay list
         func load() async {
+            await MainActor.run { self.lastSetRelayList = nil }  // Clear cache; ndb has had time to commit by now
             await self.apply(newRelayList: self.relaysToConnectTo())
         }
         

damus/Core/Storage/DamusState.swift

@@ -230,11 +230,6 @@ fileprivate extension DamusState {
         var ndb: Ndb
         var keypair: Keypair
         
-        var latestRelayListEventIdHex: String? {
-            get { self.settings.latestRelayListEventIdHex }
-            set { self.settings.latestRelayListEventIdHex = newValue }
-        }
-        
         @MainActor
         var latestContactListEvent: NostrEvent? { self.contacts.event }
         var bootstrapRelays: [RelayURL] { get_default_bootstrap_relays() }

damus/Features/Onboarding/Views/SaveKeysView.swift

@@ -166,7 +166,6 @@ struct SaveKeysView: View {
         // Save the ID to user settings so that we can easily find it later.
         let settings = UserSettingsStore.globally_load_for(pubkey: account.pubkey)
         settings.latest_contact_event_id_hex = first_contact_event.id.hex()
-        settings.latestRelayListEventIdHex = first_relay_list_event.id.hex()
     }
 
     func handle_event(relay: RelayURL, ev: NostrConnectionEvent) async {

damus/Features/Settings/Models/UserSettingsStore.swift

@@ -411,10 +411,6 @@ class UserSettingsStore: ObservableObject {
     @Setting(key: "draft_event_ids", default_value: nil)
     var draft_event_ids: [String]?
     
-    // TODO: Get rid of this once we have NostrDB query capabilities integrated
-    @Setting(key: "latest_relay_list_event_id", default_value: nil)
-    var latestRelayListEventIdHex: String?
-    
     // MARK: Helper types
     
     enum NotificationsMode: String, CaseIterable, Identifiable, StringCodable, Equatable {