refactor: reconcile duplicate LIMITS code and rename client accessory

Cleanup after adding LimitsMessage + the client-side cache:

- Remove the unused experimental LIMITS prototype
  (experimental/limits/Limits.kt + LimitProcessor.kt). Its @Serializable
  model duplicated LimitsMessage (minus auth_for_read/auth_for_write and
  the Message wiring); the processor's clamp/reject logic is superseded by
  the server-side LimitsPolicy and will be reincarnated as pure helpers on
  LimitsMessage. Both were prototypes with no references (preserved in git
  history).
- Rename the client accessory RelayLimits -> RelayLimitsTracker so it no
  longer collides on simple name with the relay-server-side
  nip01Core.relay.server.policies.RelayLimits (the operator-configured
  limits a relay enforces and advertises). Updates AppModules and the test.

No behavior change. quartz:jvmTest (RelayLimitsTrackerTest 5/5) and
amethyst play-flavor compile are green.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01464jkunWPtYhTReoc3fUQQ

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

@@ -122,7 +122,7 @@ import com.vitorpamplona.quartz.nip01Core.relay.client.INostrClient
 import com.vitorpamplona.quartz.nip01Core.relay.client.NostrClient
 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.limits.RelayLimits
+import com.vitorpamplona.quartz.nip01Core.relay.client.limits.RelayLimitsTracker
 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
@@ -712,7 +712,7 @@ class AppModules(
     val relayStats = RelayStats(client)
 
     // Caches the latest LIMITS (rights + limits) each relay advertises.
-    val relayLimits = RelayLimits(client)
+    val relayLimits = RelayLimitsTracker(client)
 
     // Resource-usage ledger: relay traffic/reconnect + connection-time,
     // foreground-time, process-CPU, and signature-verification collectors.

quartz/src/commonMain/kotlin/com/vitorpamplona/quartz/experimental/limits/LimitProcessor.kt

@@ -1,113 +0,0 @@
-/*
- * Copyright (c) 2025 Vitor Pamplona
- *
- * Permission is hereby granted, free of charge, to any person obtaining a copy of
- * this software and associated documentation files (the "Software"), to deal in
- * the Software without restriction, including without limitation the rights to use,
- * copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the
- * Software, and to permit persons to whom the Software is furnished to do so,
- * subject to the following conditions:
- *
- * The above copyright notice and this permission notice shall be included in all
- * copies or substantial portions of the Software.
- *
- * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
- * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
- * FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
- * COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
- * AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
- * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
- */
-package com.vitorpamplona.quartz.experimental.limits
-
-import com.vitorpamplona.quartz.nip01Core.core.Event
-import com.vitorpamplona.quartz.nip01Core.relay.filters.Filter
-import com.vitorpamplona.quartz.nip13Pow.pow
-import com.vitorpamplona.quartz.utils.TimeUtils
-
-class LimitProcessor {
-    fun wrapFilterToLimits(
-        filter: Filter,
-        sendingStr: String,
-        limits: Limits,
-    ): Filter? {
-        var newFilter: Filter? = filter
-
-        if (limits.canRead != null && !limits.canRead) {
-            newFilter = null
-        }
-
-        if (limits.maxLimit != null && filter.limit != null && filter.limit > limits.maxLimit) {
-            newFilter = filter.copy(limit = limits.maxLimit)
-        }
-
-        if (!limits.acceptedEventKinds.isNullOrEmpty() && !filter.kinds.isNullOrEmpty()) {
-            val intersect = filter.kinds.filter { it in limits.acceptedEventKinds }
-            if (intersect.isNotEmpty()) {
-                newFilter = filter.copy(kinds = intersect)
-            } else {
-                newFilter = null
-            }
-        }
-
-        if (!limits.blockedEventKinds.isNullOrEmpty() && !filter.kinds.isNullOrEmpty()) {
-            val intersect = filter.kinds.filter { it !in limits.blockedEventKinds }
-            if (intersect.isNotEmpty()) {
-                newFilter = filter.copy(kinds = intersect)
-            } else {
-                newFilter = null
-            }
-        }
-
-        if (limits.maxMessageLength != null && sendingStr.length > limits.maxMessageLength) {
-            // TODO: figure out how to dynamically reduce filter size
-            newFilter = null
-        }
-
-        return newFilter
-    }
-
-    fun canSendEvent(
-        ev: Event,
-        sendingStr: String,
-        limits: Limits,
-    ): Boolean {
-        if (limits.canWrite != null && !limits.canWrite) return false
-
-        if (!limits.acceptedEventKinds.isNullOrEmpty() && ev.kind !in limits.acceptedEventKinds) return false
-        if (!limits.blockedEventKinds.isNullOrEmpty() && ev.kind in limits.blockedEventKinds) return false
-
-        if (limits.minPoW != null && ev.pow() < limits.minPoW) return false
-        if (limits.maxEventTags != null && ev.tags.size > limits.maxEventTags) return false
-        if (limits.maxContentLength != null && ev.content.length > limits.maxContentLength) return false
-
-        if (limits.createdAtMillisecsAgo != null && ev.createdAt < TimeUtils.now() - limits.createdAtMillisecsAgo) return false
-        if (limits.createdAtMillisecsAhead != null && ev.createdAt > TimeUtils.now() + limits.createdAtMillisecsAhead) return false
-
-        if (limits.requiredTags != null && !matchAll(ev, limits.requiredTags)) return false
-
-        if (limits.maxMessageLength != null && sendingStr.length > limits.maxMessageLength) return false
-
-        return true
-    }
-
-    private fun matchAll(
-        ev: Event,
-        requiredTags: Array<Array<String>>,
-    ): Boolean =
-        requiredTags.all { requiredTag ->
-            if (requiredTag.isNotEmpty()) {
-                if (requiredTag.getOrNull(1) == null) {
-                    ev.tags.any { eventTag ->
-                        eventTag.getOrNull(0) == requiredTag[0]
-                    }
-                } else {
-                    ev.tags.any { eventTag ->
-                        eventTag.getOrNull(0) == requiredTag[0] && eventTag.getOrNull(1) == requiredTag[1]
-                    }
-                }
-            } else {
-                true
-            }
-        }
-}

quartz/src/commonMain/kotlin/com/vitorpamplona/quartz/experimental/limits/Limits.kt

@@ -1,44 +0,0 @@
-/*
- * Copyright (c) 2025 Vitor Pamplona
- *
- * Permission is hereby granted, free of charge, to any person obtaining a copy of
- * this software and associated documentation files (the "Software"), to deal in
- * the Software without restriction, including without limitation the rights to use,
- * copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the
- * Software, and to permit persons to whom the Software is furnished to do so,
- * subject to the following conditions:
- *
- * The above copyright notice and this permission notice shall be included in all
- * copies or substantial portions of the Software.
- *
- * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
- * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
- * FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
- * COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
- * AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
- * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
- */
-package com.vitorpamplona.quartz.experimental.limits
-
-import kotlinx.serialization.SerialName
-import kotlinx.serialization.Serializable
-
-@Serializable
-class Limits(
-    @SerialName("can_write") val canWrite: Boolean?,
-    @SerialName("can_read") val canRead: Boolean?,
-    @SerialName("accepted_event_kinds") val acceptedEventKinds: Set<Int>?,
-    @SerialName("blocked_event_kinds") val blockedEventKinds: Set<Int>?,
-    @SerialName("min_pow_difficulty") val minPoW: Int?,
-    @SerialName("max_message_length") val maxMessageLength: Int?,
-    @SerialName("max_subscriptions") val maxSubscriptions: Int?,
-    @SerialName("max_filters") val maxFilters: Int?,
-    @SerialName("max_limit") val maxLimit: Int?,
-    @SerialName("max_event_tags") val maxEventTags: Int?,
-    @SerialName("max_content_length") val maxContentLength: Int?,
-    @SerialName("created_at_msecs_ago") val createdAtMillisecsAgo: Long?,
-    @SerialName("created_at_msecs_ahead") val createdAtMillisecsAhead: Long?,
-    @SerialName("filter_rate_limit") val filterRateLimit: Long?,
-    @SerialName("publishing_rate_limit") val publishingRateLimit: Long?,
-    @SerialName("required_tags") val requiredTags: Array<Array<String>>?,
-)

quartz/src/commonMain/kotlin/com/vitorpamplona/quartz/nip01Core/relay/client/limits/RelayLimitsTracker.kt

@@ -47,8 +47,12 @@ import kotlinx.coroutines.flow.update
  * The cache is connection-scoped: a relay's entry is dropped on disconnect, so a
  * stale limit from a previous session never leaks into a new one. A fresh
  * connection re-advertises `LIMITS` on connect.
+ *
+ * Named `…Tracker` to avoid colliding with the relay-*server* side's
+ * [com.vitorpamplona.quartz.nip01Core.relay.server.policies.RelayLimits], which
+ * is the operator-configured source of truth a relay enforces and advertises.
  */
-class RelayLimits(
+class RelayLimitsTracker(
     val client: INostrClient,
 ) {
     // onIncomingMessage / onDisconnected fire on the per-relay socket dispatcher
@@ -88,13 +92,13 @@ class RelayLimits(
         }
 
     init {
-        Log.d("RelayLimits", "Init, Subscribe")
+        Log.d("RelayLimitsTracker", "Init, Subscribe")
         client.addConnectionListener(clientListener)
     }
 
     fun destroy() {
         // makes sure to run
-        Log.d("RelayLimits", "Destroy, Unsubscribe")
+        Log.d("RelayLimitsTracker", "Destroy, Unsubscribe")
         client.removeConnectionListener(clientListener)
     }
 }

quartz/src/commonTest/kotlin/com/vitorpamplona/quartz/nip01Core/relay/client/limits/RelayLimitsTrackerTest.kt

@@ -33,7 +33,7 @@ import kotlin.test.assertEquals
 import kotlin.test.assertNull
 import kotlin.test.assertTrue
 
-class RelayLimitsTest {
+class RelayLimitsTrackerTest {
     private class CapturingClient(
         private val delegate: INostrClient = EmptyNostrClient(),
     ) : INostrClient by delegate {
@@ -62,10 +62,10 @@ class RelayLimitsTest {
         override fun disconnect() = Unit
     }
 
-    private fun setup(): Pair<RelayLimits, RelayConnectionListener> {
+    private fun setup(): Pair<RelayLimitsTracker, RelayConnectionListener> {
         val client = CapturingClient()
-        val limits = RelayLimits(client)
-        val listener = client.captured ?: error("RelayLimits did not register a listener")
+        val limits = RelayLimitsTracker(client)
+        val listener = client.captured ?: error("RelayLimitsTracker did not register a listener")
         return limits to listener
     }