Make location notes robust: durable relay subscriptions, failure decay, auto-recovery (#1333)

* Make location notes robust: durable relay subscriptions, failure decay, auto-recovery

Location notes (and geohash chat / DMs) intermittently stopped showing
events because the Nostr relay layer lost subscriptions and blacklisted
relays:

- Replay active subscriptions on every relay (re)connect. Relays drop
  REQs with the socket; previously a drop silently killed the
  subscription on that relay for the rest of the session. Durable
  subscription intent now also survives disconnect()/resetAllConnections
  (background -> foreground).
- Keep failed REQ sends queued instead of dropping them.
- Raise the EOSE fallback from a fixed 2s Timer to a 10s injected
  schedule (Tor needs more than 2s), and settle EOSE trackers when a
  relay disconnects before answering so initial load doesn't stall.
- Decay "permanently failed" relay markings after a 10-minute cooldown;
  previously ~9 minutes of outage (or one DNS hiccup) excluded a relay
  until app restart, with nothing resetting it on macOS.
- Make geo relay selection deterministic (distance, then host) so
  publishers and subscribers with the same directory agree on relays.
- Post .geoRelayDirectoryDidRefresh after a directory fetch and let
  LocationNotesManager auto-resubscribe out of the "no relays" state
  instead of requiring a manual retry.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

* Guard subscription activation on connection identity

A REQ send completion from a dead socket could land after
handleDisconnection cleared the relay's subscriptions and re-mark the
subscription active, making the next connection skip the durable replay
and leave that relay silent. Only mark a subscription active if the
completing socket is still the relay's live connection.

Regression test defers send completions in the mock so the stale
completion deterministically interleaves between disconnect and
reconnect.

Addresses Codex review on #1333.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

---------

Co-authored-by: jack <jackjackbits@users.noreply.github.com>
Co-authored-by: Claude Fable 5 <noreply@anthropic.com>

bitchat/Nostr/GeoRelayDirectory.swift

@@ -7,6 +7,11 @@ import UIKit
 import AppKit
 #endif
 
+extension Notification.Name {
+    /// Posted after the geo relay directory successfully refreshes its entries.
+    static let geoRelayDirectoryDidRefresh = Notification.Name("bitchat.geoRelayDirectoryDidRefresh")
+}
+
 /// Directory of online Nostr relays with approximate GPS locations, used for geohash routing.
 struct GeoRelayDirectoryDependencies {
     var userDefaults: UserDefaults
@@ -165,33 +170,16 @@ final class GeoRelayDirectory {
     }
 
     /// Returns up to `count` relay URLs (wss://) closest to the given coordinate.
+    /// Ties break by host so every device with the same directory picks the
+    /// same relay set — publishers and subscribers must agree on relays.
     func closestRelays(toLat lat: Double, lon: Double, count: Int = 5) -> [String] {
         guard !entries.isEmpty, count > 0 else { return [] }
 
-        if entries.count <= count {
-            return entries
-                .sorted { a, b in
-                    haversineKm(lat, lon, a.lat, a.lon) < haversineKm(lat, lon, b.lat, b.lon)
-                }
-                .map { "wss://\($0.host)" }
-        }
-
-        var best: [(entry: Entry, distance: Double)] = []
-        best.reserveCapacity(count)
-
-        for entry in entries {
-            let distance = haversineKm(lat, lon, entry.lat, entry.lon)
-            if best.count < count {
-                let idx = best.firstIndex { $0.distance > distance } ?? best.count
-                best.insert((entry, distance), at: idx)
-            } else if let worstDistance = best.last?.distance, distance < worstDistance {
-                let idx = best.firstIndex { $0.distance > distance } ?? best.count
-                best.insert((entry, distance), at: idx)
-                best.removeLast()
-            }
-        }
-
-        return best.map { "wss://\($0.entry.host)" }
+        return entries
+            .map { (entry: $0, distance: haversineKm(lat, lon, $0.lat, $0.lon)) }
+            .sorted { ($0.distance, $0.entry.host) < ($1.distance, $1.entry.host) }
+            .prefix(count)
+            .map { "wss://\($0.entry.host)" }
     }
 
     // MARK: - Remote Fetch
@@ -289,6 +277,8 @@ final class GeoRelayDirectory {
         isFetching = false
         retryAttempt = 0
         cancelRetry()
+        // Let waiters (e.g. location notes stuck in a "no relays" state) retry.
+        dependencies.notificationCenter.post(name: .geoRelayDirectoryDidRefresh, object: nil)
     }
 
     @MainActor