fix(send-message): treat ntfy topic targets as explicit

tools/send_message_tool.py

@@ -143,7 +143,7 @@ SEND_MESSAGE_SCHEMA = {
             },
             "target": {
                 "type": "string",
-                "description": "Delivery target. Format: 'platform' (uses home channel), 'platform:#channel-name', 'platform:chat_id', or 'platform:chat_id:thread_id' for Telegram topics and Discord threads. Examples: 'telegram', 'telegram:-1001234567890:17585', 'discord:999888777:555444333', 'discord:#bot-home', 'slack:#engineering', 'signal:+155****4567', 'matrix:!roomid:server.org', 'matrix:@user:server.org', 'yuanbao:direct:<account_id>' (DM), 'yuanbao:group:<group_code>' (group chat)"
+                "description": "Delivery target. Format: 'platform' (uses home channel), 'platform:#channel-name', 'platform:chat_id', or 'platform:chat_id:thread_id' for Telegram topics and Discord threads. Examples: 'telegram', 'telegram:-1001234567890:17585', 'discord:999888777:555444333', 'discord:#bot-home', 'slack:#engineering', 'signal:+155****4567', 'matrix:!roomid:server.org', 'matrix:@user:server.org', 'ntfy:alerts-channel' (explicit ntfy topic), 'yuanbao:direct:<account_id>' (DM), 'yuanbao:group:<group_code>' (group chat)"
             },
             "message": {
                 "type": "string",
@@ -395,6 +395,10 @@ def _parse_target_ref(platform_name: str, target_ref: str):
         if target_ref.strip().isdigit():
             return f"group:{target_ref.strip()}", None, True
         return None, None, False
+    if platform_name == "ntfy":
+        topic = target_ref.strip()
+        if topic:
+            return topic, None, True
     if platform_name == "email":
         match = _EMAIL_TARGET_RE.fullmatch(target_ref)
         if match:
@@ -502,6 +506,7 @@ async def _send_via_adapter(
          the runner weakref is ``None``).
       3. A descriptive error explaining both options.
     """
+    platform_name = platform.value if hasattr(platform, "value") else str(platform)
     runner = None
     try:
         from gateway.run import _gateway_runner_ref
@@ -516,7 +521,13 @@ async def _send_via_adapter(
             adapter = None
         if adapter is not None:
             try:
-                metadata = {"thread_id": thread_id} if thread_id else None
+                metadata = {}
+                if thread_id:
+                    metadata["thread_id"] = thread_id
+                if platform_name == "ntfy" and chat_id:
+                    metadata["publish_topic"] = chat_id
+                if not metadata:
+                    metadata = None
                 result = await adapter.send(chat_id=chat_id, content=chunk, metadata=metadata)
             except asyncio.CancelledError:
                 raise
@@ -526,7 +537,6 @@ async def _send_via_adapter(
                 return {"success": True, "message_id": result.message_id}
             return {"error": f"Adapter send failed: {result.error}"}
 
-    platform_name = platform.value if hasattr(platform, "value") else str(platform)
     entry = None
     try:
         from gateway.platform_registry import platform_registry