Add Bot API 10.2 Ephemeral Messages support example

New EphemeralMessagesBot demonstrating the 36.0.0 ephemeral-message API:
- sendTextMessage with receiverUserId + callbackQueryId to send a message
  visible only to one user in a group, in response to a callback query
- PossiblyEphemeralMessage detection of ephemeral messages
- editEphemeralMessageText / deleteEphemeralMessage addressed by
  chatId + receiverUserId + ephemeralMessageId
- reply() smart-branch replying ephemerally to an ephemeral message, and the
  explicit replyToEphemeral form
- BotCommand.isEphemeral flag

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

EphemeralMessagesBot/build.gradle

@@ -0,0 +1,21 @@
+buildscript {
+    repositories {
+        mavenCentral()
+    }
+
+    dependencies {
+        classpath "org.jetbrains.kotlin:kotlin-gradle-plugin:$kotlin_version"
+    }
+}
+
+apply plugin: 'kotlin'
+apply plugin: 'application'
+
+mainClassName="EphemeralMessagesBotKt"
+
+
+dependencies {
+    implementation "org.jetbrains.kotlin:kotlin-stdlib:$kotlin_version"
+
+    implementation "dev.inmo:tgbotapi:$telegram_bot_api_version"
+}