test(ntfy): cover echo-tag filter; tag standalone send path

Adds tests for the echo-loop fix (outgoing X-Tags header, inbound skip
on tagged events, genuine tags pass through) and extends the tag to the
out-of-process _standalone_send() path so cron / send_message deliveries
to a self-subscribed topic are also skipped. Maps both contributors in
release.py AUTHOR_MAP.

Co-authored-by: liuhao1024 <sunsky.lau@gmail.com>

plugins/platforms/ntfy/adapter.py

@@ -530,7 +530,7 @@ async def _standalone_send(
     markdown_env = os.getenv("NTFY_MARKDOWN", "").strip().lower()
     markdown_enabled = bool(extra.get("markdown")) or markdown_env in ("1", "true", "yes")
 
-    headers = {"Content-Type": "text/plain; charset=utf-8", **_build_auth_header(token)}
+    headers = {"Content-Type": "text/plain; charset=utf-8", "X-Tags": _ECHO_TAG, **_build_auth_header(token)}
     if markdown_enabled:
         headers["X-Markdown"] = "true"