NIP-30: use Address type for emoji-set reference instead of raw string

Makes the API safer: callers can't accidentally pass an unparsed or
malformed identifier. EmojiUrlTag.emojiSet is now Address?, serialized
via toValue() and parsed via Address.parse() (which rejects anything
that isn't a well-formed kind:pubkey:dTag).

quartz/src/commonMain/kotlin/com/vitorpamplona/quartz/nip30CustomEmoji/EmojiUrlTag.kt

@@ -21,12 +21,13 @@
 package com.vitorpamplona.quartz.nip30CustomEmoji
 
 import androidx.compose.runtime.Immutable
+import com.vitorpamplona.quartz.nip01Core.core.Address
 
 @Immutable
 data class EmojiUrlTag(
     val code: String,
     val url: String,
-    val emojiSet: String? = null,
+    val emojiSet: Address? = null,
 ) {
     fun encode(): String = ":$code:$url"
 
@@ -34,7 +35,7 @@ data class EmojiUrlTag(
 
     fun toTagArray() =
         if (emojiSet != null) {
-            arrayOf(TAG_NAME, code, url, emojiSet)
+            arrayOf(TAG_NAME, code, url, emojiSet.toValue())
         } else {
             arrayOf(TAG_NAME, code, url)
         }
@@ -60,7 +61,7 @@ data class EmojiUrlTag(
 
         fun parse(tag: Array<String>): EmojiUrlTag? =
             if (tag.size > 2 && tag[0] == TAG_NAME) {
-                EmojiUrlTag(tag[1], tag[2], tag.getOrNull(3))
+                EmojiUrlTag(tag[1], tag[2], tag.getOrNull(3)?.let(Address::parse))
             } else {
                 null
             }

quartz/src/commonMain/kotlin/com/vitorpamplona/quartz/nip30CustomEmoji/TagArrayBuilderExt.kt

@@ -20,6 +20,7 @@
  */
 package com.vitorpamplona.quartz.nip30CustomEmoji
 
+import com.vitorpamplona.quartz.nip01Core.core.Address
 import com.vitorpamplona.quartz.nip01Core.core.Event
 import com.vitorpamplona.quartz.nip01Core.core.TagArrayBuilder
 
@@ -28,7 +29,7 @@ fun <T : Event> TagArrayBuilder<T>.emoji(tag: EmojiUrlTag) = add(tag.toTagArray(
 fun <T : Event> TagArrayBuilder<T>.emoji(
     code: String,
     url: String,
-    emojiSet: String? = null,
+    emojiSet: Address? = null,
 ) = add(EmojiUrlTag(code, url, emojiSet).toTagArray())
 
 fun <T : Event> TagArrayBuilder<T>.emojis(tags: List<EmojiUrlTag>) = addAll(tags.map { it.toTagArray() })

quartz/src/commonTest/kotlin/com/vitorpamplona/quartz/nip30CustomEmoji/Nip30Test.kt

@@ -20,6 +20,7 @@
  */
 package com.vitorpamplona.quartz.nip30CustomEmoji
 
+import com.vitorpamplona.quartz.nip01Core.core.Address
 import kotlin.test.Test
 import kotlin.test.assertContentEquals
 import kotlin.test.assertEquals
@@ -28,6 +29,10 @@ import kotlin.test.assertNull
 import kotlin.test.assertTrue
 
 class Nip30Test {
+    companion object {
+        private const val TEST_PUBKEY = "0000000000000000000000000000000000000000000000000000000000000abc"
+    }
+
     @Test()
     fun parseEmoji() {
         val tags = mapOf(":soapbox:" to "http://soapbox")
@@ -177,17 +182,25 @@ class Nip30Test {
 
     @Test
     fun emojiTagWithEmojiSetRoundtrip() {
-        val setAddress = "30030:abc123:emojis-fall"
+        val setAddress = Address(30030, TEST_PUBKEY, "emojis-fall")
         val tag = EmojiUrlTag("soapbox", "http://soapbox", setAddress)
-        assertContentEquals(arrayOf("emoji", "soapbox", "http://soapbox", setAddress), tag.toTagArray())
+        assertContentEquals(arrayOf("emoji", "soapbox", "http://soapbox", setAddress.toValue()), tag.toTagArray())
         assertEquals(tag, EmojiUrlTag.parse(tag.toTagArray()))
     }
 
     @Test
     fun parseIgnoresTrailingFields() {
-        val tag = arrayOf("emoji", "soapbox", "http://soapbox", "30030:abc123:pack", "extra")
+        val setAddress = Address(30030, TEST_PUBKEY, "pack")
+        val tag = arrayOf("emoji", "soapbox", "http://soapbox", setAddress.toValue(), "extra")
         val parsed = EmojiUrlTag.parse(tag)
-        assertEquals(EmojiUrlTag("soapbox", "http://soapbox", "30030:abc123:pack"), parsed)
+        assertEquals(EmojiUrlTag("soapbox", "http://soapbox", setAddress), parsed)
+    }
+
+    @Test
+    fun parseMalformedEmojiSetAddressYieldsNull() {
+        val tag = arrayOf("emoji", "soapbox", "http://soapbox", "not-an-address")
+        val parsed = EmojiUrlTag.parse(tag)
+        assertEquals(EmojiUrlTag("soapbox", "http://soapbox", null), parsed)
     }
 
     @Test