refactor: clear final java.* imports from commons/commonMain

Three changes that bring commons/commonMain to zero java.* imports
(down from 18 at the start of Phase 2).

- EventListMatchingFilter, NoteListMatchingFilter: moved to jvmAndroid.
  Both use ConcurrentSkipListSet + SortedSet for ordered concurrent
  iteration, and their only consumer is LocalCache in the Android app.
  iOS-time we can revisit if a KMP ordered concurrent set is needed.

- Note.kt's BigDecimal: switch import from java.math.BigDecimal to
  quartz's existing expect/actual com.vitorpamplona.quartz.utils.BigDecimal.
  BigDecimal.ZERO -> BigDecimal(0); BigDecimal.valueOf(longVal) ->
  BigDecimal(longVal) (the expect class already has the Long
  constructor). NoteOnchainZapTest gets the same treatment.

- Adds two top-level extensions in quartz commonMain (separate
  BigDecimalOps.kt file to avoid the duplicate-JVM-classname collision
  with the existing BigDecimal.kt actuals):
    operator fun BigDecimal.plus(other: BigDecimal)
    operator fun BigDecimal.minus(other: BigDecimal)
  Lets += / + / - continue to work on commonMain BigDecimal values.

Commons/commonMain is now structurally iOS-ready as far as the
java.* import audit can tell. Remaining iOS work: actually flip on
the iOS targets, see what UI / dep transitives break, and address.

commons/src/commonMain/kotlin/com/vitorpamplona/amethyst/commons/model/Note.kt

@@ -64,17 +64,18 @@ import com.vitorpamplona.quartz.nip57Zaps.LnZapRequestEvent
 import com.vitorpamplona.quartz.nip59Giftwrap.WrappedEvent
 import com.vitorpamplona.quartz.nip72ModCommunities.approval.CommunityPostApprovalEvent
 import com.vitorpamplona.quartz.nip72ModCommunities.definition.CommunityDefinitionEvent
+import com.vitorpamplona.quartz.utils.BigDecimal
 import com.vitorpamplona.quartz.utils.TimeUtils
 import com.vitorpamplona.quartz.utils.anyAsync
 import com.vitorpamplona.quartz.utils.containsAny
 import com.vitorpamplona.quartz.utils.launchAndWaitAll
+import com.vitorpamplona.quartz.utils.plus
 import kotlinx.coroutines.CancellationException
 import kotlinx.coroutines.ExperimentalCoroutinesApi
 import kotlinx.coroutines.flow.Flow
 import kotlinx.coroutines.flow.MutableStateFlow
 import kotlinx.coroutines.flow.combine
 import kotlinx.coroutines.flow.flatMapLatest
-import java.math.BigDecimal
 import kotlin.concurrent.Volatile
 
 interface NotesGatherer {
@@ -162,7 +163,7 @@ open class Note(
     var zaps = mapOf<Note, Note?>()
         private set
 
-    var zapsAmount: BigDecimal = BigDecimal.ZERO
+    var zapsAmount: BigDecimal = BigDecimal(0)
 
     /**
      * NIP-BC onchain zaps targeting this note.
@@ -357,7 +358,7 @@ open class Note(
         onchainZaps = mapOf()
         onchainZapResolved = false
         zapPayments = mapOf()
-        zapsAmount = BigDecimal.ZERO
+        zapsAmount = BigDecimal(0)
         relays = listOf()
 
         if (repliesChanged) flowSet?.replies?.invalidateData()
@@ -743,13 +744,13 @@ open class Note(
             }.flatten()
 
     private fun updateZapTotal() {
-        var sumOfAmounts = BigDecimal.ZERO
+        var sumOfAmounts = BigDecimal(0)
 
         // Regular Zap Receipts
         zaps.forEach {
             val noteEvent = it.value?.event
             if (noteEvent is LnZapEvent) {
-                sumOfAmounts += noteEvent.amount ?: BigDecimal.ZERO
+                sumOfAmounts += noteEvent.amount ?: BigDecimal(0)
             }
         }
 
@@ -757,7 +758,7 @@ open class Note(
         // Unverified/pending entries are tracked but excluded from the total per spec.
         onchainZaps.values.forEach { entry ->
             if (entry.status == OnchainZapStatus.CONFIRMED) {
-                sumOfAmounts += BigDecimal.valueOf(entry.verifiedSats)
+                sumOfAmounts += BigDecimal(entry.verifiedSats)
             }
         }
 
@@ -895,7 +896,7 @@ open class Note(
                 pledgeValue != null && it.author == user
             }
 
-    fun pledgedAmountByOthers(): BigDecimal = replies.sumOf { it.event?.addedRewardValue() ?: BigDecimal.ZERO }
+    fun pledgedAmountByOthers(): BigDecimal = replies.sumOf { it.event?.addedRewardValue() ?: BigDecimal(0) }
 
     fun hasAnyReports(): Boolean {
         val dayAgo = TimeUtils.oneDayAgo()
@@ -984,7 +985,7 @@ open class Note(
         boosts = emptyList()
         reports = emptyMap()
         zaps = emptyMap()
-        zapsAmount = BigDecimal.ZERO
+        zapsAmount = BigDecimal(0)
     }
 
     fun isHiddenFor(accountChoices: LiveHiddenUsers): Boolean {

commons/src/commonTest/kotlin/com/vitorpamplona/amethyst/commons/model/NoteOnchainZapTest.kt

@@ -21,7 +21,7 @@
 package com.vitorpamplona.amethyst.commons.model
 
 import com.vitorpamplona.quartz.nip01Core.core.HexKey
-import java.math.BigDecimal
+import com.vitorpamplona.quartz.utils.BigDecimal
 import kotlin.test.Test
 import kotlin.test.assertEquals
 import kotlin.test.assertFalse
@@ -67,7 +67,7 @@ class NoteOnchainZapTest {
         assertEquals(1000L, entry?.claimedSats)
         assertEquals(0L, entry?.verifiedSats)
         assertEquals(OnchainZapStatus.UNVERIFIED, entry?.status)
-        assertEquals(BigDecimal.ZERO, target.zapsAmount)
+        assertEquals(BigDecimal(0), target.zapsAmount)
     }
 
     @Test
@@ -82,7 +82,7 @@ class NoteOnchainZapTest {
         assertSame(src, entry?.source)
         assertEquals(1000L, entry?.verifiedSats)
         assertEquals(OnchainZapStatus.PENDING, entry?.status)
-        assertEquals(BigDecimal.ZERO, target.zapsAmount)
+        assertEquals(BigDecimal(0), target.zapsAmount)
     }
 
     @Test
@@ -93,7 +93,7 @@ class NoteOnchainZapTest {
         target.addOnchainZap(src, "tx1", claimedSats = 5000L, verifiedSats = 5000L, status = OnchainZapStatus.CONFIRMED)
 
         assertEquals(OnchainZapStatus.CONFIRMED, target.onchainZaps["tx1"]?.status)
-        assertEquals(BigDecimal.valueOf(5000L), target.zapsAmount)
+        assertEquals(BigDecimal(5000L), target.zapsAmount)
     }
 
     @Test
@@ -109,7 +109,7 @@ class NoteOnchainZapTest {
         assertSame(secondSrc, entry?.source)
         assertEquals(OnchainZapStatus.PENDING, entry?.status)
         assertEquals(2400L, entry?.verifiedSats)
-        assertEquals(BigDecimal.ZERO, target.zapsAmount)
+        assertEquals(BigDecimal(0), target.zapsAmount)
     }
 
     @Test
@@ -124,7 +124,7 @@ class NoteOnchainZapTest {
         val entry = target.onchainZaps["tx1"]
         assertSame(secondSrc, entry?.source)
         assertEquals(OnchainZapStatus.CONFIRMED, entry?.status)
-        assertEquals(BigDecimal.valueOf(2500L), target.zapsAmount)
+        assertEquals(BigDecimal(2500L), target.zapsAmount)
     }
 
     @Test
@@ -139,7 +139,7 @@ class NoteOnchainZapTest {
         val entry = target.onchainZaps["tx1"]
         assertSame(firstSrc, entry?.source)
         assertEquals(OnchainZapStatus.CONFIRMED, entry?.status)
-        assertEquals(BigDecimal.valueOf(7500L), target.zapsAmount)
+        assertEquals(BigDecimal(7500L), target.zapsAmount)
     }
 
     @Test
@@ -188,7 +188,7 @@ class NoteOnchainZapTest {
         val entry = target.onchainZaps["tx1"]
         assertSame(firstSrc, entry?.source)
         assertEquals(999L, entry?.verifiedSats)
-        assertEquals(BigDecimal.valueOf(999L), target.zapsAmount)
+        assertEquals(BigDecimal(999L), target.zapsAmount)
     }
 
     @Test
@@ -206,7 +206,7 @@ class NoteOnchainZapTest {
 
         val entry = target.onchainZaps["tx1"]
         assertSame(secondSrc, entry?.source)
-        assertEquals(BigDecimal.valueOf(1000L), target.zapsAmount)
+        assertEquals(BigDecimal(1000L), target.zapsAmount)
     }
 
     @Test
@@ -224,7 +224,7 @@ class NoteOnchainZapTest {
         val secondEntry = target.onchainZaps["tx1"]
 
         assertSame(firstEntry, secondEntry)
-        assertEquals(BigDecimal.valueOf(100L), target.zapsAmount)
+        assertEquals(BigDecimal(100L), target.zapsAmount)
     }
 
     @Test
@@ -238,13 +238,13 @@ class NoteOnchainZapTest {
 
         target.addOnchainZap(src, "tx1", claimedSats = 4200L, verifiedSats = 4200L, status = OnchainZapStatus.PENDING)
         // PENDING entries don't contribute to total per spec.
-        assertEquals(BigDecimal.ZERO, target.zapsAmount)
+        assertEquals(BigDecimal(0), target.zapsAmount)
         assertNotNull(target.onchainZaps["tx1"])
 
         target.removeOnchainZapForSource("tx1", srcKey)
 
         assertNull(target.onchainZaps["tx1"])
-        assertEquals(BigDecimal.ZERO, target.zapsAmount)
+        assertEquals(BigDecimal(0), target.zapsAmount)
     }
 
     @Test
@@ -277,13 +277,13 @@ class NoteOnchainZapTest {
         val src = sourceNote(srcKey)
 
         target.addOnchainZap(src, "tx1", claimedSats = 4200L, verifiedSats = 4200L, status = OnchainZapStatus.CONFIRMED)
-        assertEquals(BigDecimal.valueOf(4200L), target.zapsAmount)
+        assertEquals(BigDecimal(4200L), target.zapsAmount)
 
         target.removeOnchainZapForSource("tx1", srcKey)
 
         assertNotNull(target.onchainZaps["tx1"])
         assertEquals(OnchainZapStatus.CONFIRMED, target.onchainZaps["tx1"]?.status)
-        assertEquals(BigDecimal.valueOf(4200L), target.zapsAmount)
+        assertEquals(BigDecimal(4200L), target.zapsAmount)
     }
 
     @Test
@@ -342,7 +342,7 @@ class NoteOnchainZapTest {
         target.addOnchainZap(sourceNote("82".repeat(32)), "tx3", claimedSats = 9999L, verifiedSats = 9999L, status = OnchainZapStatus.PENDING)
         target.addOnchainZap(sourceNote("93".repeat(32)), "tx4", claimedSats = 1234L, verifiedSats = 0L, status = OnchainZapStatus.UNVERIFIED)
 
-        assertEquals(BigDecimal.valueOf(3000L), target.zapsAmount)
+        assertEquals(BigDecimal(3000L), target.zapsAmount)
         assertEquals(4, target.onchainZaps.size)
         assertTrue(target.onchainZaps.containsKey("tx3"))
         assertTrue(target.onchainZaps.containsKey("tx4"))

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

@@ -0,0 +1,25 @@
+/*
+ * 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.utils
+
+operator fun BigDecimal.plus(other: BigDecimal): BigDecimal = add(other)
+
+operator fun BigDecimal.minus(other: BigDecimal): BigDecimal = subtract(other)