feat(sse): sync protocol failure type

Author: loong10k

src/main/java/io/github/easy4j/hermes/api/sse/SseProtocolException.java

@@ -0,0 +1,16 @@
+package io.github.easy4j.hermes.api.sse;
+
+/** Signals an SSE protocol or frame-bound violation separately from transport and consumer failures. */
+public final class SseProtocolException extends RuntimeException {
+    private final String eventId;
+    private final String eventName;
+
+    public SseProtocolException(SseFrame frame, String message) {
+        super(message);
+        this.eventId = frame == null ? null : frame.getId();
+        this.eventName = frame == null ? null : frame.getEvent();
+    }
+
+    public String getEventId() { return eventId; }
+    public String getEventName() { return eventName; }
+}