perf: adopt CachingEventDecoder in Android, Desktop, and amy clients

Passes decoder = CachingEventDecoder() at all four NostrClient
construction sites: the Android app pool (AppModules), the Android
crawl client (buildCrawlClient — Event Sync / Cashu discovery, the
duplicate-heaviest path), the desktop RelayConnectionManager, and
amy's Context. Duplicate EVENT frames (14-57% of production traffic)
now skip the full JSON re-parse; dispatch semantics unchanged.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_018saXqYfAa3RvSJoDXK591R

amethyst/src/main/java/com/vitorpamplona/amethyst/AppModules.kt

@@ -100,6 +100,7 @@ import com.vitorpamplona.quartz.nip01Core.relay.client.accessories.RelayLogger
 import com.vitorpamplona.quartz.nip01Core.relay.client.accessories.RelayOfflineTracker
 import com.vitorpamplona.quartz.nip01Core.relay.client.reqs.stats.RelayReqStats
 import com.vitorpamplona.quartz.nip01Core.relay.client.stats.RelayStats
+import com.vitorpamplona.quartz.nip01Core.relay.commands.toClient.CachingEventDecoder
 import com.vitorpamplona.quartz.nip03Timestamp.VerificationStateCache
 import com.vitorpamplona.quartz.nip03Timestamp.okhttp.OkHttpBitcoinExplorer
 import com.vitorpamplona.quartz.nip03Timestamp.ots.OtsBlockHeightCache
@@ -499,8 +500,10 @@ class AppModules(
             OkHttpLnurlEndpointResolver(roleBasedHttpClientBuilder::okHttpClientForMoney)
     }
 
-    // Provides a relay pool
-    val client: INostrClient = NostrClient(websocketBuilder, applicationIOScope)
+    // Provides a relay pool. The caching decoder skips re-parsing EVENT frames
+    // that arrive again via another subscription or relay (14-57% of frames in
+    // production measurements).
+    val client: INostrClient = NostrClient(websocketBuilder, applicationIOScope, CachingEventDecoder())
 
     // Self-heals the "Tor Active but every circuit dead" state the lifecycle watchdogs can't
     // see (they only arm while Connecting). Watches Tor-routed relay outcomes and, when enough

amethyst/src/main/java/com/vitorpamplona/amethyst/ui/screen/loggedIn/AccountViewModel.kt

@@ -112,6 +112,7 @@ import com.vitorpamplona.quartz.nip01Core.relay.client.NostrClient
 import com.vitorpamplona.quartz.nip01Core.relay.client.accessories.RelayOfflineTracker
 import com.vitorpamplona.quartz.nip01Core.relay.client.auth.EmptyIAuthStatus
 import com.vitorpamplona.quartz.nip01Core.relay.client.auth.RelayAuthenticator
+import com.vitorpamplona.quartz.nip01Core.relay.commands.toClient.CachingEventDecoder
 import com.vitorpamplona.quartz.nip01Core.relay.normalizer.NormalizedRelayUrl
 import com.vitorpamplona.quartz.nip01Core.signers.NostrSignerInternal
 import com.vitorpamplona.quartz.nip01Core.signers.SignerExceptions
@@ -310,8 +311,9 @@ class AccountViewModel(
         // but uses a SupervisorJob so child failures are independent.
         val customScope = CoroutineScope(viewModelScope.coroutineContext + SupervisorJob())
 
-        // Provides a relay pool
-        val newClient = NostrClient(Amethyst.instance.websocketBuilder, customScope)
+        // Provides a relay pool. Crawls hit many relays with overlapping
+        // filters, so the duplicate-frame decoder pays off most here.
+        val newClient = NostrClient(Amethyst.instance.websocketBuilder, customScope, CachingEventDecoder())
 
         // Authenticates with relays (registers itself with the client).
         RelayAuthenticator(

cli/src/main/kotlin/com/vitorpamplona/amethyst/cli/Context.kt

@@ -45,6 +45,7 @@ import com.vitorpamplona.quartz.nip01Core.relay.client.NostrClient
 import com.vitorpamplona.quartz.nip01Core.relay.client.accessories.publishAndConfirmDetailed
 import com.vitorpamplona.quartz.nip01Core.relay.client.reqs.SubscriptionListener
 import com.vitorpamplona.quartz.nip01Core.relay.client.single.newSubId
+import com.vitorpamplona.quartz.nip01Core.relay.commands.toClient.CachingEventDecoder
 import com.vitorpamplona.quartz.nip01Core.relay.filters.Filter
 import com.vitorpamplona.quartz.nip01Core.relay.normalizer.NormalizedRelayUrl
 import com.vitorpamplona.quartz.nip01Core.relay.normalizer.RelayUrlNormalizer
@@ -115,6 +116,9 @@ class Context(
     val client: NostrClient =
         NostrClient(
             websocketBuilder = BasicOkHttpWebSocket.Builder { okhttp },
+            // Skips re-parsing EVENT frames that arrive again via another
+            // subscription or relay.
+            decoder = CachingEventDecoder(),
         )
 
     /**

desktopApp/src/jvmMain/kotlin/com/vitorpamplona/amethyst/desktop/network/RelayConnectionManager.kt

@@ -25,6 +25,7 @@ import com.vitorpamplona.quartz.nip01Core.relay.client.NostrClient
 import com.vitorpamplona.quartz.nip01Core.relay.client.listeners.RelayConnectionListener
 import com.vitorpamplona.quartz.nip01Core.relay.client.reqs.SubscriptionListener
 import com.vitorpamplona.quartz.nip01Core.relay.client.single.IRelayClient
+import com.vitorpamplona.quartz.nip01Core.relay.commands.toClient.CachingEventDecoder
 import com.vitorpamplona.quartz.nip01Core.relay.commands.toClient.EventMessage
 import com.vitorpamplona.quartz.nip01Core.relay.commands.toClient.Message
 import com.vitorpamplona.quartz.nip01Core.relay.commands.toRelay.Command
@@ -56,7 +57,9 @@ data class RelayMetrics(
 open class RelayConnectionManager(
     websocketBuilder: WebsocketBuilder,
 ) : RelayConnectionListener {
-    private val _client = NostrClient(websocketBuilder)
+    // The caching decoder skips re-parsing EVENT frames that arrive again via
+    // another subscription or relay.
+    private val _client = NostrClient(websocketBuilder, decoder = CachingEventDecoder())
 
     /** Exposes the underlying INostrClient for subscription coordinators */
     val client: com.vitorpamplona.quartz.nip01Core.relay.client.INostrClient get() = _client