Annotate IntentData and AmberBunkerRequest with @Immutable

Tells the Compose compiler these data classes are stable so that
composables receiving List<IntentData> or List<AmberBunkerRequest>
can be skipped during recomposition when the list reference hasn't
changed, avoiding the 'unstable parameter' performance warning.

https://claude.ai/code/session_01PRSKjmFms1Tj1QJ5FhfqZm

app/src/main/java/com/greenart7c3/nostrsigner/models/AmberBunkerRequest.kt

@@ -1,5 +1,6 @@
 package com.greenart7c3.nostrsigner.models
 
+import androidx.compose.runtime.Immutable
 import com.vitorpamplona.quartz.nip01Core.core.Event
 import com.vitorpamplona.quartz.nip01Core.relay.normalizer.NormalizedRelayUrl
 import com.vitorpamplona.quartz.nip46RemoteSigner.BunkerRequest
@@ -9,6 +10,7 @@ enum class EncryptionType {
     NIP04,
 }
 
+@Immutable
 data class AmberBunkerRequest(
     val request: BunkerRequest,
     val localKey: String,

app/src/main/java/com/greenart7c3/nostrsigner/models/IntentData.kt

@@ -1,8 +1,10 @@
 package com.greenart7c3.nostrsigner.models
 
+import androidx.compose.runtime.Immutable
 import com.vitorpamplona.quartz.nip01Core.core.Event
 import com.vitorpamplona.quartz.nip01Core.core.HexKey
 
+@Immutable
 data class IntentData(
     val data: String,
     val name: String,