fix: handle checked JsonProcessingException in serializePayload

writeValueAsString throws checked JsonProcessingException which was
unhandled, causing a compile error. Wrapped in try/catch, rethrowing
as IllegalStateException.

docs/ja-JP/skills/quarkus-patterns/SKILL.md

@@ -185,8 +185,11 @@ public class EventService {
     }
     
     private String serializePayload(Object payload) {
-        // JSONシリアライゼーション
-        return objectMapper.writeValueAsString(payload);
+        try {
+            return objectMapper.writeValueAsString(payload);
+        } catch (JsonProcessingException e) {
+            throw new IllegalStateException("Failed to serialize event payload", e);
+        }
     }
 }
 ```

docs/tr/skills/quarkus-patterns/SKILL.md

@@ -185,8 +185,11 @@ public class EventService {
     }
     
     private String serializePayload(Object payload) {
-        // JSON serileştirme
-        return objectMapper.writeValueAsString(payload);
+        try {
+            return objectMapper.writeValueAsString(payload);
+        } catch (JsonProcessingException e) {
+            throw new IllegalStateException("Failed to serialize event payload", e);
+        }
     }
 }
 ```

docs/zh-CN/skills/quarkus-patterns/SKILL.md

@@ -185,8 +185,11 @@ public class EventService {
     }
     
     private String serializePayload(Object payload) {
-        // JSON序列化
-        return objectMapper.writeValueAsString(payload);
+        try {
+            return objectMapper.writeValueAsString(payload);
+        } catch (JsonProcessingException e) {
+            throw new IllegalStateException("Failed to serialize event payload", e);
+        }
     }
 }
 ```

skills/quarkus-patterns/SKILL.md

@@ -187,8 +187,11 @@ public class EventService {
     }
     
     private String serializePayload(Object payload) {
-        // JSON serialization
-        return objectMapper.writeValueAsString(payload);
+        try {
+            return objectMapper.writeValueAsString(payload);
+        } catch (JsonProcessingException e) {
+            throw new IllegalStateException("Failed to serialize event payload", e);
+        }
     }
 }
 ```