perf(relay): drop per-op allocations on the frame + search paths

Three hot-path allocation cuts the SmallReqFloorBenchmark stages flagged:

- strippingSearchExtensions: index-loop guard returns the same list with
  zero allocation when no filter carries a search term (every non-search
  REQ/COUNT/snapshot, the overwhelming majority).
- EoseMessage/OkMessage: direct-buildString wire form on the escape-free
  fast path (EOSE per REQ, OK per publish), skipping the generic
  serializer's node tree; exotic subIds/reasons fall back. Shared
  isEscapeFreeAscii helper in WireJson.kt, mirroring NegMsgMessage.

Verified: quartz relay.server + message-frame suites (110 tests).

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01RzkoN3SJHCZWRAiadXXG4w

quartz/src/commonMain/kotlin/com/vitorpamplona/quartz/nip01Core/relay/commands/toClient/EoseMessage.kt

@@ -25,6 +25,22 @@ class EoseMessage(
 ) : Message {
     override fun label() = LABEL
 
+    /**
+     * Wire form is `["EOSE","<subId>"]` — sent once per REQ, so it is on
+     * the per-subscription floor. Splice it directly when [subId] needs no
+     * escaping (the common case: client-chosen sub ids are short ASCII),
+     * skipping the generic serializer's node tree. Byte-identical output;
+     * any exotic subId falls back.
+     */
+    override fun toJson(): String {
+        if (!isEscapeFreeAscii(subId)) return super.toJson()
+        return buildString(subId.length + 12) {
+            append("[\"EOSE\",\"")
+            append(subId)
+            append("\"]")
+        }
+    }
+
     companion object {
         const val LABEL = "EOSE"
     }

quartz/src/commonMain/kotlin/com/vitorpamplona/quartz/nip01Core/relay/commands/toClient/OkMessage.kt

@@ -29,6 +29,25 @@ class OkMessage(
 ) : Message {
     override fun label() = LABEL
 
+    /**
+     * Wire form is `["OK","<eventId>",<true|false>,"<message>"]` — sent
+     * once per published EVENT. [eventId] is validated hex (always
+     * escape-free); splice directly when [message] also needs no escaping,
+     * which covers the empty-string success ack and the plain-ASCII
+     * rejection reasons. Byte-identical output; a reason with quotes or
+     * non-ASCII falls back to the generic serializer.
+     */
+    override fun toJson(): String {
+        if (!isEscapeFreeAscii(message)) return super.toJson()
+        return buildString(eventId.length + message.length + 20) {
+            append("[\"OK\",\"")
+            append(eventId)
+            append(if (success) "\",true,\"" else "\",false,\"")
+            append(message)
+            append("\"]")
+        }
+    }
+
     companion object {
         const val LABEL = "OK"
 

quartz/src/commonMain/kotlin/com/vitorpamplona/quartz/nip01Core/relay/commands/toClient/WireJson.kt

@@ -0,0 +1,36 @@
+/*
+ * 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.nip01Core.relay.commands.toClient
+
+/**
+ * True when every char of [s] is printable ASCII (0x20–0x7e) and not a JSON
+ * metacharacter (`"` / `\`) — i.e. exactly the bytes a JSON string encoder
+ * would emit verbatim between the quotes. Frame builders use this to gate a
+ * direct-`buildString` fast path against the generic serializer: when it holds
+ * the spliced output is byte-identical, and any exotic value (control chars,
+ * quotes, non-ASCII) falls back to the escaping serializer.
+ */
+internal fun isEscapeFreeAscii(s: String): Boolean {
+    for (c in s) {
+        if (c < ' ' || c > '~' || c == '"' || c == '\\') return false
+    }
+    return true
+}

quartz/src/commonMain/kotlin/com/vitorpamplona/quartz/nip50Search/SearchQuery.kt

@@ -202,8 +202,20 @@ fun Filter.strippingSearchExtensions(): Filter {
 /**
  * Applies [strippingSearchExtensions] to every filter, returning this
  * same list when no filter carried extension tokens.
+ *
+ * This runs on every REQ/COUNT/snapshot, and the overwhelming majority
+ * carry no `search` term at all, so the no-search case must not allocate:
+ * bail before building any list when nothing could be stripped.
  */
 fun List<Filter>.strippingSearchExtensions(): List<Filter> {
+    var hasSearch = false
+    for (i in indices) {
+        if (!this[i].search.isNullOrEmpty()) {
+            hasSearch = true
+            break
+        }
+    }
+    if (!hasSearch) return this
     var changed = false
     val out =
         map {