Merge pull request #2114 from greenart7c3/claude/implement-payment-targets-VzxXc

Add payment targets feature with NIP-A3 support

quartz/src/commonMain/kotlin/com/vitorpamplona/quartz/experimental/nipA3/PaymentTargetTag.kt

@@ -35,11 +35,10 @@ class PaymentTargetTag {
             ensure(tag.has(1)) { return null }
             ensure(tag[0] == TAG_NAME) { return null }
             ensure(tag[1].isNotEmpty()) { return null }
+            ensure(tag.has(2)) { return null }
             ensure(tag[2].isNotEmpty()) { return null }
 
-            val paymentTarget = PaymentTarget(tag[1], tag[2])
-
-            return paymentTarget
+            return PaymentTarget(tag[1], tag[2])
         }
 
         fun assemble(paymentTarget: PaymentTarget) = arrayOf(TAG_NAME, paymentTarget.type, paymentTarget.authority)

quartz/src/commonMain/kotlin/com/vitorpamplona/quartz/experimental/nipA3/PaymentTargetsEvent.kt

@@ -34,6 +34,8 @@ class PaymentTargetsEvent(
     content: String,
     sig: HexKey,
 ) : BaseReplaceableEvent(id, pubKey, createdAt, KIND, tags, content, sig) {
+    fun paymentTargets(): List<PaymentTarget> = tags.mapNotNull { PaymentTargetTag.parse(it) }
+
     companion object {
         const val KIND = 10133