fix: kind-38000 audit findings

- Unrecognised 38000s fell back to a plain Event, which stores do not key
  by `d` (they test `is AddressableEvent`): a spam bot republishing one
  address kept every copy, an `a`-tag deletion missed them, and a newer
  junk version never replaced an older recommendation. They are now
  UnrecognizedKind38000Event — addressable, never indexed, no card — and
  EventCache files them as addressables instead of logging each one's
  JSON at WARN.
- The card's blank-line regex rescanned long whitespace runs from every
  position: a crafted ~64 KB description froze the main thread for
  seconds. Collapsed line by line instead.
- The fee printed Double.toString ("4.21%" beside German "100.000 sats",
  "NaN%" for junk). New locale-aware formatDecimal (expect/actual);
  non-finite or negative fees are dropped.
- The status badge and the closing-time line read the clock at different
  moments, and a market declared closed before its end read "Closed <a
  future date>". Both now read the same moment; a closed-early market
  states no closing time.
- Outcomes are (id, label): `resolution` names the id, the card shows
  the label — `["outcome","opt1","Foundry USA"]` and `{"id":"A",
  "label":"Foundry"}` resolved to "A" now mark their winner. Deduped by
  set and capped at 64 against crafted floods.
- isMintRecommendation accepts any `k` naming a mint kind (not only the
  first) and a recommendation that names its mint only by `a`.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_012CsFEX4ZT8mL1r8h2M6qfH

commons/src/commonMain/kotlin/com/vitorpamplona/amethyst/commons/model/cache/EventCache.kt

@@ -390,6 +390,7 @@ import com.vitorpamplona.quartz.nip85TrustedAssertions.users.UserAssertionEvent
 import com.vitorpamplona.quartz.nip87Ecash.cashu.CashuMintEvent
 import com.vitorpamplona.quartz.nip87Ecash.fedimint.FedimintEvent
 import com.vitorpamplona.quartz.nip87Ecash.recommendation.MintRecommendationEvent
+import com.vitorpamplona.quartz.nip87Ecash.recommendation.UnrecognizedKind38000Event
 import com.vitorpamplona.quartz.nip88Polls.poll.PollEvent
 import com.vitorpamplona.quartz.nip88Polls.response.PollResponseEvent
 import com.vitorpamplona.quartz.nip89AppHandlers.definition.AppDefinitionEvent
@@ -3967,6 +3968,8 @@ open class EventCache :
                 // Other apps' kind-38000 formats, split from mint recommendations by EventFactory.
                 is BallotEvent,
                 is PredictionMarketEvent,
+                // Unread junk on 38000 still supersedes an older version at its address.
+                is UnrecognizedKind38000Event,
                 -> consumeBaseReplaceable(event, relay, wasVerified)
 
                 // ============================================================

commons/src/commonMain/kotlin/com/vitorpamplona/amethyst/commons/util/GroupedNumber.kt

@@ -22,3 +22,9 @@ package com.vitorpamplona.amethyst.commons.util
 
 /** [value] with the locale's digit grouping: `1,234,567` in English, `1.234.567` in German. */
 expect fun formatGrouped(value: Long): String
+
+/** [value] with the locale's decimal mark and at most [maxFractionDigits] digits after it: `4.21` in English, `4,21` in German. */
+expect fun formatDecimal(
+    value: Double,
+    maxFractionDigits: Int,
+): String

commons/src/iosMain/kotlin/com/vitorpamplona/amethyst/commons/util/GroupedNumber.ios.kt

@@ -23,9 +23,22 @@ package com.vitorpamplona.amethyst.commons.util
 import platform.Foundation.NSNumber
 import platform.Foundation.NSNumberFormatter
 import platform.Foundation.NSNumberFormatterDecimalStyle
+import platform.Foundation.numberWithDouble
 import platform.Foundation.numberWithLongLong
 
 actual fun formatGrouped(value: Long): String {
     val formatter = NSNumberFormatter().apply { numberStyle = NSNumberFormatterDecimalStyle }
     return formatter.stringFromNumber(NSNumber.numberWithLongLong(value)) ?: value.toString()
 }
+
+actual fun formatDecimal(
+    value: Double,
+    maxFractionDigits: Int,
+): String {
+    val formatter =
+        NSNumberFormatter().apply {
+            numberStyle = NSNumberFormatterDecimalStyle
+            maximumFractionDigits = maxFractionDigits.toULong()
+        }
+    return formatter.stringFromNumber(NSNumber.numberWithDouble(value)) ?: value.toString()
+}

commons/src/jvmAndroid/kotlin/com/vitorpamplona/amethyst/commons/util/GroupedNumber.jvmAndroid.kt

@@ -23,3 +23,8 @@ package com.vitorpamplona.amethyst.commons.util
 import java.text.NumberFormat
 
 actual fun formatGrouped(value: Long): String = NumberFormat.getNumberInstance().format(value)
+
+actual fun formatDecimal(
+    value: Double,
+    maxFractionDigits: Int,
+): String = NumberFormat.getNumberInstance().apply { maximumFractionDigits = maxFractionDigits }.format(value)

commonsUI/src/commonMain/kotlin/com/vitorpamplona/amethyst/commons/ui/note/types/PredictionMarket.kt

@@ -80,9 +80,11 @@ import com.vitorpamplona.amethyst.commons.ui.theme.redColorOnSecondSurface
 import com.vitorpamplona.amethyst.commons.ui.theme.replyModifier
 import com.vitorpamplona.amethyst.commons.ui.theme.subtleBorder
 import com.vitorpamplona.amethyst.commons.ui.theme.warningColorOnSecondSurface
+import com.vitorpamplona.amethyst.commons.util.formatDecimal
 import com.vitorpamplona.amethyst.commons.util.formatGrouped
 import com.vitorpamplona.amethyst.commons.viewmodels.AccountViewModel
 import com.vitorpamplona.quartz.experimental.predictionMarkets.PredictionMarketEvent
+import com.vitorpamplona.quartz.experimental.predictionMarkets.PredictionMarketOutcome
 import com.vitorpamplona.quartz.experimental.predictionMarkets.PredictionMarketStatus
 import com.vitorpamplona.quartz.utils.TimeUtils
 import kotlinx.collections.immutable.ImmutableList
@@ -117,7 +119,7 @@ fun RenderPredictionMarket(
 private class PredictionMarketCardState(
     val title: String?,
     val description: String?,
-    val outcomes: ImmutableList<String>,
+    val outcomes: ImmutableList<PredictionMarketOutcome>,
     val status: PredictionMarketStatus?,
     val resolution: String?,
     val endsAt: Long?,
@@ -128,11 +130,13 @@ private class PredictionMarketCardState(
     val maxBetSats: String?,
     val feePercent: String?,
     val cancelReason: String?,
+    /** The moment the status was read, so the closing-time line agrees with the status badge. */
+    val now: Long,
 ) {
-    fun isWinner(outcome: String) = resolution != null && outcome.equals(resolution, ignoreCase = true)
+    fun isWinner(outcome: PredictionMarketOutcome) = outcome.isNamedBy(resolution)
 
     /** Two outcomes, one a yes and one a no — "YES"/"NO", "Yes (stays online)"/"No (goes offline)". */
-    val isBinary = outcomes.size == 2 && outcomes.any(::isYes) && outcomes.any(::isNo)
+    val isBinary = outcomes.size == 2 && outcomes.any { isYes(it.label) } && outcomes.any { isNo(it.label) }
 
     companion object {
         fun from(
@@ -141,7 +145,7 @@ private class PredictionMarketCardState(
         ) = PredictionMarketCardState(
             title = event.title() ?: socialPostHeadline(event.content),
             description = event.description()?.let(::collapseBlankLines),
-            outcomes = event.outcomes().toImmutableList(),
+            outcomes = event.outcomeOptions().toImmutableList(),
             status = event.status(now),
             resolution = event.resolution(),
             endsAt = event.endsAt(),
@@ -151,6 +155,7 @@ private class PredictionMarketCardState(
             maxBetSats = event.maxBetSats()?.let(::formatGrouped),
             feePercent = event.feePercent()?.let(::formatPercent),
             cancelReason = event.cancelReason(),
+            now = now,
         )
 
         fun isYes(outcome: String) = YES.containsMatchIn(outcome)
@@ -166,19 +171,21 @@ private class PredictionMarketCardState(
             return content.lineSequence().firstOrNull { it.isNotBlank() }?.trim()
         }
 
-        /** 4.21 → "4.21%", 2.0 → "2%". */
-        private fun formatPercent(value: Double): String {
-            val asLong = value.toLong()
-            return if (value == asLong.toDouble()) "$asLong%" else "$value%"
-        }
+        /** 4.21 → "4.21%" ("4,21%" in German), 2.0 → "2%"; nothing for NaN, infinities or a negative. */
+        private fun formatPercent(value: Double): String? = if (value.isFinite() && value >= 0) "${formatDecimal(value, 2)}%" else null
 
         /**
          * BAO's descriptions carry paragraph breaks ("…UTC.\n\nSource of Truth: …"); clipped to a
          * few lines, a blank line reads as a hole in the card. One line break each, never a gap.
          */
-        private fun collapseBlankLines(text: String): String = text.trim().replace(BLANK_LINES, "\n")
-
-        private val BLANK_LINES = Regex("""\s*\n\s*\n\s*""")
+        private fun collapseBlankLines(text: String): String =
+            // Line by line rather than a regex: a run of whitespace in a crafted event made the
+            // obvious pattern rescan it from every position — seconds on the main thread.
+            text
+                .lineSequence()
+                .map { it.trim() }
+                .filter { it.isNotEmpty() }
+                .joinToString("\n")
     }
 }
 
@@ -227,7 +234,7 @@ fun PredictionMarketCard(
             if (state.status == PredictionMarketStatus.CANCELLED) {
                 state.cancelReason?.let { CancelReason(it) }
             } else {
-                state.endsAt?.let { ClosingTime(it, state.status) }
+                state.endsAt?.let { ClosingTime(it, state.status, state.now) }
             }
 
             MarketTerms(state.minBetSats, state.maxBetSats, state.feePercent)
@@ -341,7 +348,7 @@ private fun MarketOutcomes(state: PredictionMarketCardState) {
         verticalArrangement = Arrangement.spacedBy(6.dp),
     ) {
         shown.forEach { outcome ->
-            OutcomeChip(outcome, isWinner = state.isWinner(outcome), muted = muted)
+            OutcomeChip(outcome.label, isWinner = state.isWinner(outcome), muted = muted)
         }
         if (hidden > 0) {
             Text(
@@ -370,7 +377,7 @@ private fun BinaryOutcomes(
             val isWinner = state.isWinner(outcome)
             val quiet = muted || (decided && !isWinner)
             val side =
-                if (PredictionMarketCardState.isYes(outcome)) {
+                if (PredictionMarketCardState.isYes(outcome.label)) {
                     MaterialTheme.colorScheme.allGoodColor
                 } else {
                     MaterialTheme.colorScheme.redColorOnSecondSurface
@@ -397,7 +404,7 @@ private fun BinaryOutcomes(
                     )
                 }
                 Text(
-                    text = outcome,
+                    text = outcome.label,
                     style = MaterialTheme.typography.labelLarge,
                     fontWeight = FontWeight.Bold,
                     color = color,
@@ -460,8 +467,12 @@ private fun OutcomeChip(
 private fun ClosingTime(
     endsAt: Long,
     status: PredictionMarketStatus?,
+    now: Long,
 ) {
-    val stillOpen = status == PredictionMarketStatus.OPEN && endsAt > TimeUtils.now()
+    // Read against the same moment as the status badge, so the two never disagree. A market
+    // declared closed or settled before its end has no closing time worth stating.
+    val stillOpen = status == PredictionMarketStatus.OPEN && endsAt > now
+    if (!stillOpen && endsAt > now) return
     val text =
         if (stillOpen) {
             stringRes(Res.string.prediction_market_closes_in, timeAheadNoDot(endsAt))

quartz/src/commonMain/kotlin/com/vitorpamplona/quartz/experimental/predictionMarkets/PredictionMarketDetails.kt

@@ -38,7 +38,7 @@ import kotlinx.serialization.json.longOrNull
 class PredictionMarketDetails(
     val title: String?,
     val description: String?,
-    val outcomes: List<String>,
+    val outcomes: List<PredictionMarketOutcome>,
     val category: String?,
     val status: String?,
     val reason: String?,
@@ -95,24 +95,40 @@ class PredictionMarketDetails(
         private fun JsonObject.double(key: String): Double? = primitive(key)?.doubleOrNull
 
         /**
-         * `outcomes` as display strings: a plain string per outcome (current shape), or an object
-         * per outcome whose `label` (else `id`, `name`) names it (BAO Fund and first shapes).
+         * `outcomes`: a plain string per outcome (current shape), or an object per outcome with an
+         * `id` and a `label` (else `name`) (BAO Fund and first shapes). Once per id, at most
+         * [PredictionMarketOutcome.MAX].
          */
-        private fun JsonObject.outcomes(): List<String> {
+        private fun JsonObject.outcomes(): List<PredictionMarketOutcome> {
             val array = this["outcomes"] as? JsonArray ?: return emptyList()
-            val result = ArrayList<String>(array.size)
+            val result = LinkedHashMap<String, PredictionMarketOutcome>(minOf(array.size, PredictionMarketOutcome.MAX))
             for (element in array) {
-                val name = outcomeName(element)
-                if (name != null && name !in result) result.add(name)
+                if (result.size >= PredictionMarketOutcome.MAX) break
+                val outcome = outcomeOf(element) ?: continue
+                if (outcome.id !in result) result[outcome.id] = outcome
             }
-            return result
+            return result.values.toList()
         }
 
-        private fun outcomeName(element: JsonElement): String? =
+        private fun outcomeOf(element: JsonElement): PredictionMarketOutcome? =
             when (element) {
-                is JsonPrimitive -> element.takeIf { it.isString }?.content?.ifBlank { null }
-                is JsonObject -> element.text("label") ?: element.text("id") ?: element.text("name")
-                else -> null
+                is JsonPrimitive -> {
+                    element
+                        .takeIf { it.isString }
+                        ?.content
+                        ?.ifBlank { null }
+                        ?.let { PredictionMarketOutcome(it, it) }
+                }
+
+                is JsonObject -> {
+                    val label = element.text("label") ?: element.text("name")
+                    val id = element.text("id") ?: label
+                    if (id == null) null else PredictionMarketOutcome(id, label ?: id)
+                }
+
+                else -> {
+                    null
+                }
             }
     }
 }

quartz/src/commonMain/kotlin/com/vitorpamplona/quartz/experimental/predictionMarkets/PredictionMarketEvent.kt

@@ -81,12 +81,15 @@ class PredictionMarketEvent(
 
     fun description() = dataDetails?.description ?: contentDetails?.description
 
-    /** The outcomes one can bet on: the `outcome` tags, else the JSON `outcomes`. */
-    fun outcomes(): List<String> =
+    /** The outcomes one can bet on, id and label: the `outcome` tags, else the JSON `outcomes`. */
+    fun outcomeOptions(): List<PredictionMarketOutcome> =
         tags.marketOutcomes().ifEmpty {
             dataDetails?.outcomes?.ifEmpty { null } ?: contentDetails?.outcomes ?: emptyList()
         }
 
+    /** The outcomes as a reader sees them, by label. */
+    fun outcomes(): List<String> = outcomeOptions().map { it.label }
+
     /** The winning outcome, once resolved. */
     fun resolution() = tags.marketResolution() ?: dataDetails?.resolution ?: contentDetails?.resolution
 

quartz/src/commonMain/kotlin/com/vitorpamplona/quartz/experimental/predictionMarkets/PredictionMarketOutcome.kt

@@ -0,0 +1,42 @@
+/*
+ * 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.predictionMarkets
+
+import androidx.compose.runtime.Immutable
+
+/**
+ * One answer a market can resolve to. BAO writes some as a bare word (`["outcome","YES"]`, a
+ * JSON string) and some as an id with a label (`["outcome","opt1","Foundry USA"]`,
+ * `{"id":"A","label":"Yes"}`): a `resolution` names the [id], a reader is shown the [label].
+ */
+@Immutable
+data class PredictionMarketOutcome(
+    val id: String,
+    val label: String,
+) {
+    /** Whether [resolution] names this outcome — by its id, or by its label as some markets do. */
+    fun isNamedBy(resolution: String?): Boolean = resolution != null && (id.equals(resolution, ignoreCase = true) || label.equals(resolution, ignoreCase = true))
+
+    companion object {
+        /** More than any market offers; a crafted event with thousands is cut here. */
+        const val MAX = 64
+    }
+}

quartz/src/commonMain/kotlin/com/vitorpamplona/quartz/experimental/predictionMarkets/TagArrayExt.kt

@@ -57,15 +57,17 @@ fun TagArray.marketNetwork() = firstNonBlankValue("network", "n")
 fun TagArray.marketCategory() = firstNonBlankValue("category", "c")
 
 /**
- * Every `outcome` tag's value, in order. The BAO Fund shape writes `["outcome", id, label]`;
- * the id is what a `resolution` names, so it is the one returned.
+ * Every `outcome` tag, in order, once per id and at most [PredictionMarketOutcome.MAX]. The BAO
+ * Fund shape writes `["outcome", id, label]`; the current shape a bare word, its own label.
  */
-fun TagArray.marketOutcomes(): List<String> {
-    val result = ArrayList<String>(2)
+fun TagArray.marketOutcomes(): List<PredictionMarketOutcome> {
+    val result = LinkedHashMap<String, PredictionMarketOutcome>(4)
     fastForEach {
-        if (it.size > 1 && it[0] == "outcome" && it[1].isNotBlank() && it[1] !in result) result.add(it[1])
+        if (result.size < PredictionMarketOutcome.MAX && it.size > 1 && it[0] == "outcome" && it[1].isNotBlank() && it[1] !in result) {
+            result[it[1]] = PredictionMarketOutcome(it[1], it.getOrNull(2)?.ifBlank { null } ?: it[1])
+        }
     }
-    return result
+    return result.values.toList()
 }
 
 /** The winning outcome, once the market is resolved. */

quartz/src/commonMain/kotlin/com/vitorpamplona/quartz/nip87Ecash/recommendation/MintRecommendationEvent.kt

@@ -26,7 +26,6 @@ import com.vitorpamplona.quartz.nip01Core.core.HexKey
 import com.vitorpamplona.quartz.nip01Core.core.TagArray
 import com.vitorpamplona.quartz.nip01Core.core.TagArrayBuilder
 import com.vitorpamplona.quartz.nip01Core.core.fastAny
-import com.vitorpamplona.quartz.nip01Core.core.fastFirstOrNull
 import com.vitorpamplona.quartz.nip01Core.signers.eventTemplate
 import com.vitorpamplona.quartz.nip50Search.IndexableFieldVisitor
 import com.vitorpamplona.quartz.nip50Search.SearchableEvent
@@ -73,17 +72,29 @@ class MintRecommendationEvent(
          * the kind number alone does not say what an event is. A recommendation names the kind of
          * the mint it recommends in its `k` tag — 38172 (Cashu) or 38173 (Fedimint). Some early
          * recommendations carry no `k` at all; those are accepted when they point at a mint URL
-         * (`u`). A `k` naming anything else is not a mint recommendation, whatever else it carries.
+         * (`u`) or at the mint's announcement (an `a` to a 38172/38173 address). A `k` naming
+         * only other kinds is not a mint recommendation, whatever else it carries.
          */
         fun isMintRecommendation(tags: TagArray): Boolean {
-            val kTag = tags.fastFirstOrNull { it.size > 1 && it[0] == "k" }
-            if (kTag != null) {
-                val mintKind = kTag[1].toIntOrNull()
-                return mintKind == CashuMintEvent.KIND || mintKind == FedimintEvent.KIND
+            // Any `k` naming a mint's kind: a relay answering `#k=38172` may hand back an event
+            // whose first `k` is something else.
+            if (tags.fastAny { it.size > 1 && it[0] == "k" && it[1].toIntOrNull().isMintKind() }) return true
+            if (tags.fastAny { it.size > 1 && it[0] == "k" && it[1].isNotBlank() }) return false
+            return tags.fastAny {
+                it.size > 1 &&
+                    (
+                        (it[0] == MintUrlTag.TAG_NAME && it[1].isNotBlank()) ||
+                            // The mint's own announcement, by address: `38172:<pubkey>:<d>`.
+                            (it[0] == "a" && (it[1].startsWith(CASHU_ADDRESS) || it[1].startsWith(FEDIMINT_ADDRESS)))
+                    )
             }
-            return tags.fastAny { it.size > 1 && it[0] == MintUrlTag.TAG_NAME && it[1].isNotBlank() }
         }
 
+        private fun Int?.isMintKind() = this == CashuMintEvent.KIND || this == FedimintEvent.KIND
+
+        private val CASHU_ADDRESS = "${CashuMintEvent.KIND}:"
+        private val FEDIMINT_ADDRESS = "${FedimintEvent.KIND}:"
+
         /**
          * [mintKind] must be [CashuMintEvent.KIND] or [FedimintEvent.KIND]: the `k` tag it writes is
          * what [isMintRecommendation] reads back, so any other value signs into a plain kind-38000

quartz/src/commonMain/kotlin/com/vitorpamplona/quartz/nip87Ecash/recommendation/UnrecognizedKind38000Event.kt

@@ -0,0 +1,44 @@
+/*
+ * 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.nip87Ecash.recommendation
+
+import androidx.compose.runtime.Immutable
+import com.vitorpamplona.quartz.nip01Core.core.BaseAddressableEvent
+import com.vitorpamplona.quartz.nip01Core.core.HexKey
+
+/**
+ * A kind-38000 event that is none of the formats Amethyst reads on that number — not a NIP-87
+ * [MintRecommendationEvent], a ballot or a prediction market. Most of them are `d`-only spam.
+ *
+ * Still addressable, because the kind is: stores key it by `d` (`event is AddressableEvent`), so
+ * a newer version replaces an older one and an `a`-tag deletion reaches it, as NIP-01 requires
+ * of every kind in 30000–39999. Not a SearchableEvent, so it is never indexed, and no card is
+ * drawn for it.
+ */
+@Immutable
+class UnrecognizedKind38000Event(
+    id: HexKey,
+    pubKey: HexKey,
+    createdAt: Long,
+    tags: Array<Array<String>>,
+    content: String,
+    sig: HexKey,
+) : BaseAddressableEvent(id, pubKey, createdAt, MintRecommendationEvent.KIND, tags, content, sig)

quartz/src/commonMain/kotlin/com/vitorpamplona/quartz/utils/EventFactory.kt

@@ -372,6 +372,7 @@ import com.vitorpamplona.quartz.nip85TrustedAssertions.users.UserAssertionEvent
 import com.vitorpamplona.quartz.nip87Ecash.cashu.CashuMintEvent
 import com.vitorpamplona.quartz.nip87Ecash.fedimint.FedimintEvent
 import com.vitorpamplona.quartz.nip87Ecash.recommendation.MintRecommendationEvent
+import com.vitorpamplona.quartz.nip87Ecash.recommendation.UnrecognizedKind38000Event
 import com.vitorpamplona.quartz.nip88Polls.poll.PollEvent
 import com.vitorpamplona.quartz.nip88Polls.response.PollResponseEvent
 import com.vitorpamplona.quartz.nip89AppHandlers.definition.AppDefinitionEvent
@@ -762,14 +763,15 @@ class EventFactory {
                 // ballots, and most of what a big relay holds for it is spam (`d`-only "sybil test
                 // votes"). Parsing all of it as a recommendation rendered markets, ballots and spam
                 // as ecash mint cards. Disambiguate by tags, recommendation first — its `k` (the
-                // recommended mint's kind) or, on old events without one, its `u` (mint URL) — and
-                // fall back to a plain Event so junk gets no card and no search index entry.
+                // recommended mint's kind) or, on old events without one, its `u` (mint URL) or the
+                // mint's `a` — and fall back to UnrecognizedKind38000Event: still addressable, so
+                // stores replace and delete it by `d`, but never indexed and drawn as no card.
                 MintRecommendationEvent.KIND ->
                     when {
                         MintRecommendationEvent.isMintRecommendation(tags) -> MintRecommendationEvent(id, pubKey, createdAt, tags, content, sig)
                         BallotEvent.isBallot(tags) -> BallotEvent(id, pubKey, createdAt, tags, content, sig)
                         PredictionMarketEvent.isPredictionMarket(tags) -> PredictionMarketEvent(id, pubKey, createdAt, tags, content, sig)
-                        else -> Event(id, pubKey, createdAt, kind, tags, content, sig)
+                        else -> UnrecognizedKind38000Event(id, pubKey, createdAt, tags, content, sig)
                     }
                 MediaFollowListEvent.KIND -> MediaFollowListEvent(id, pubKey, createdAt, tags, content, sig)
                 MediaStarterPackEvent.KIND -> MediaStarterPackEvent(id, pubKey, createdAt, tags, content, sig)

quartz/src/commonTest/kotlin/com/vitorpamplona/quartz/experimental/predictionMarkets/PredictionMarketEventTest.kt

@@ -281,4 +281,33 @@ class PredictionMarketEventTest {
             assertEquals(1, seen)
         }
     }
+
+    @Test
+    fun outcomesKeepTheirIdForTheWinnerAndShowTheirLabel() {
+        // `resolution` names the id; a reader is shown the label.
+        val tagged =
+            market(
+                arrayOf(
+                    arrayOf("market", "m"),
+                    arrayOf("outcome", "opt1", "Foundry USA"),
+                    arrayOf("outcome", "opt2", "AntPool"),
+                    arrayOf("resolution", "opt1"),
+                ),
+                "",
+            )
+        assertEquals(listOf("Foundry USA", "AntPool"), tagged.outcomes())
+        val winner = tagged.outcomeOptions().single { it.isNamedBy(tagged.resolution()) }
+        assertEquals(PredictionMarketOutcome("opt1", "Foundry USA"), winner)
+
+        val json = market(arrayOf(arrayOf("market", "m")), """{"outcomes":[{"id":"A","label":"Foundry"},{"id":"B","label":"Other"}]}""")
+        assertEquals(listOf("Foundry", "Other"), json.outcomes())
+        assertTrue(json.outcomeOptions().first().isNamedBy("a"))
+    }
+
+    @Test
+    fun aCraftedFloodOfOutcomesIsCut() {
+        val flood = Array(5000) { arrayOf("outcome", "o$it") }
+        val event = market(arrayOf(arrayOf("market", "m"), *flood), "")
+        assertEquals(PredictionMarketOutcome.MAX, event.outcomeOptions().size)
+    }
 }

quartz/src/commonTest/kotlin/com/vitorpamplona/quartz/utils/EventFactoryKind38000Test.kt

@@ -22,6 +22,7 @@ package com.vitorpamplona.quartz.utils
 
 import com.vitorpamplona.quartz.experimental.ballots.BallotEvent
 import com.vitorpamplona.quartz.experimental.predictionMarkets.PredictionMarketEvent
+import com.vitorpamplona.quartz.nip01Core.core.AddressableEvent
 import com.vitorpamplona.quartz.nip01Core.core.Event
 import com.vitorpamplona.quartz.nip01Core.crypto.verify
 import com.vitorpamplona.quartz.nip01Core.signers.NostrSignerSync
@@ -29,6 +30,7 @@ import com.vitorpamplona.quartz.nip50Search.SearchableEvent
 import com.vitorpamplona.quartz.nip87Ecash.cashu.CashuMintEvent
 import com.vitorpamplona.quartz.nip87Ecash.fedimint.FedimintEvent
 import com.vitorpamplona.quartz.nip87Ecash.recommendation.MintRecommendationEvent
+import com.vitorpamplona.quartz.nip87Ecash.recommendation.UnrecognizedKind38000Event
 import kotlin.test.Test
 import kotlin.test.assertEquals
 import kotlin.test.assertFalse
@@ -105,29 +107,39 @@ class EventFactoryKind38000Test {
     }
 
     @Test
-    fun spamAndOneOffsArePlainEvents() {
+    fun spamAndOneOffsAreUnrecognizedButStillAddressable() {
         listOf(
             Kind38000Fixtures.SPAM_SYBIL_VOTE,
             Kind38000Fixtures.SPAM_APP_MANIFEST,
         ).forEach {
             val event = parse(it)
-            assertEquals(Event::class, event::class)
+            assertIs<UnrecognizedKind38000Event>(event)
+            // Stores key 30000–39999 by `d` only when the event is addressable: replacement and
+            // `a`-tag deletion must still reach the spam.
+            assertIs<AddressableEvent>(event)
             assertFalse(event is SearchableEvent)
         }
     }
 
     @Test
-    fun aKNamingAnotherKindIsNotARecommendationEvenWithAMintUrl() {
-        assertEquals(Event::class, build(arrayOf("k", "1"), arrayOf("u", "https://mint.example"))::class)
-        // The first k decides.
-        assertEquals(Event::class, build(arrayOf("k", "1"), arrayOf("k", "38172"))::class)
+    fun aKNamingOnlyOtherKindsIsNotARecommendationEvenWithAMintUrl() {
+        assertIs<UnrecognizedKind38000Event>(build(arrayOf("k", "1"), arrayOf("u", "https://mint.example")))
+        // Any k naming a mint kind counts, wherever it sits.
+        assertIs<MintRecommendationEvent>(build(arrayOf("k", "1"), arrayOf("k", "38172")))
         assertIs<MintRecommendationEvent>(build(arrayOf("k", "38173"), arrayOf("k", "1")))
     }
 
+    @Test
+    fun aRecommendationNamingItsMintOnlyByAddressIsOne() {
+        assertIs<MintRecommendationEvent>(build(arrayOf("d", "x"), arrayOf("a", "38172:${"a".repeat(64)}:x")))
+        assertIs<MintRecommendationEvent>(build(arrayOf("d", "x"), arrayOf("a", "38173:${"a".repeat(64)}:x")))
+        assertIs<UnrecognizedKind38000Event>(build(arrayOf("d", "x"), arrayOf("a", "30023:${"a".repeat(64)}:x")))
+    }
+
     @Test
     fun aBlankMintUrlWithoutKIsNotARecommendation() {
-        assertEquals(Event::class, build(arrayOf("d", "x"), arrayOf("u", " "))::class)
-        assertEquals(Event::class, build(arrayOf("u"))::class)
+        assertEquals(UnrecognizedKind38000Event::class, build(arrayOf("d", "x"), arrayOf("u", " "))::class)
+        assertEquals(UnrecognizedKind38000Event::class, build(arrayOf("u"))::class)
     }
 
     @Test
@@ -142,7 +154,7 @@ class EventFactoryKind38000Test {
 
     @Test
     fun aBlankElectionIsNotABallot() {
-        assertEquals(Event::class, build(arrayOf("election", ""))::class)
+        assertEquals(UnrecognizedKind38000Event::class, build(arrayOf("election", ""))::class)
     }
 
     @Test
@@ -151,10 +163,10 @@ class EventFactoryKind38000Test {
         assertIs<PredictionMarketEvent>(build(arrayOf("outcome", "YES"), arrayOf("outcome", "NO")))
         assertIs<PredictionMarketEvent>(build(arrayOf("type", "binary"), arrayOf("end", "1")))
 
-        assertEquals(Event::class, build(arrayOf("market", " "))::class)
-        assertEquals(Event::class, build(arrayOf("outcome", "YES"))::class)
-        assertEquals(Event::class, build(arrayOf("type", "binary"))::class)
-        assertEquals(Event::class, build(arrayOf("end", "1"))::class)
+        assertEquals(UnrecognizedKind38000Event::class, build(arrayOf("market", " "))::class)
+        assertEquals(UnrecognizedKind38000Event::class, build(arrayOf("outcome", "YES"))::class)
+        assertEquals(UnrecognizedKind38000Event::class, build(arrayOf("type", "binary"))::class)
+        assertEquals(UnrecognizedKind38000Event::class, build(arrayOf("end", "1"))::class)
     }
 
     @Test