fix(rcon): validate offline badge targets

GiveBadge could treat a missing offline user as eligible for a badge and insert through a nullable user subquery. Depending on SQL mode this could fail late or persist an orphaned user_id value. Resolve the offline user first, return HABBO_NOT_FOUND when absent, and insert badges with the resolved user id only.

Emulator/src/test/java/com/eu/habbo/messages/rcon/GiveBadgeContractTest.java

@@ -0,0 +1,27 @@
+package com.eu.habbo.messages.rcon;
+
+import org.junit.jupiter.api.Test;
+
+import java.nio.file.Files;
+import java.nio.file.Path;
+
+import static org.junit.jupiter.api.Assertions.assertFalse;
+import static org.junit.jupiter.api.Assertions.assertTrue;
+
+class GiveBadgeContractTest {
+    private static String giveBadgeSource() throws Exception {
+        return Files.readString(Path.of("src/main/java/com/eu/habbo/messages/rcon/GiveBadge.java"));
+    }
+
+    @Test
+    void offlineBadgeGrantRequiresExistingUserBeforeInsert() throws Exception {
+        String source = giveBadgeSource();
+
+        assertTrue(source.contains("HabboManager.getOfflineHabboInfo(json.user_id)"),
+                "Offline RCON badge grants must verify the target user exists");
+        assertTrue(source.contains("RCONMessage.HABBO_NOT_FOUND"),
+                "Offline RCON badge grants must report missing users");
+        assertFalse(source.contains("(SELECT id FROM users WHERE users.id = ? LIMIT 1)"),
+                "Offline RCON badge grants must not insert through a nullable user subquery");
+    }
+}