fix(gateway): linearize tool-progress bubbles with content messages (#17280)

After PR #7885 (97b0cd51e) added content-side segment breaks for
natural mid-turn assistant messages, the tool-progress task in
gateway/run.py was not updated to match. progress_msg_id and
progress_lines persisted for the whole run, so after a tool batch
produced bubble B1 followed by content bubble C1, the next tool.started
kept editing the OLD bubble B1 above C1 — making the chat appear out
of order on Telegram, Discord, and Slack.

Add on_new_message callback to GatewayStreamConsumer, fired at the
four sites where a fresh content bubble lands on the platform:
  - _send_or_edit first-send branch (NOT edits)
  - _send_commentary
  - _send_new_chunk (overflow split)
  - each successful chunk of _send_fallback_final

Gateway supplies a lambda that enqueues ('__reset__',) into the
progress_queue. send_progress_messages() handles the marker in both
the main loop and the CancelledError drain path, clearing
progress_msg_id, progress_lines, and the dedup state so the next
tool.started opens a fresh bubble below the new content.

Result: each tool batch appears in chronological order below the
preceding content. When no content appears between tool batches,
tools still group in one bubble (CLI-style compactness).

Co-authored-by: teknium1 <teknium@users.noreply.github.com>

gateway/stream_consumer.py

@@ -91,11 +91,20 @@ class GatewayStreamConsumer:
         chat_id: str,
         config: Optional[StreamConsumerConfig] = None,
         metadata: Optional[dict] = None,
+        on_new_message: Optional[callable] = None,
     ):
         self.adapter = adapter
         self.chat_id = chat_id
         self.cfg = config or StreamConsumerConfig()
         self.metadata = metadata
+        # Fired whenever a fresh content bubble is created on the platform
+        # (first-send of a new message, commentary, overflow chunk, or
+        # fallback continuation). The gateway uses this to linearize the
+        # tool-progress bubble: when content resumes after a tool batch,
+        # the next tool.started should open a NEW progress bubble below
+        # the content, not edit the old bubble above it.
+        # Called with no arguments. Exceptions are swallowed.
+        self._on_new_message = on_new_message
         self._queue: queue.Queue = queue.Queue()
         self._accumulated = ""
         self._message_id: Optional[str] = None
@@ -146,6 +155,16 @@ class GatewayStreamConsumer:
         if text:
             self._queue.put((_COMMENTARY, text))
 
+    def _notify_new_message(self) -> None:
+        """Fire the on_new_message callback, swallowing any errors."""
+        cb = self._on_new_message
+        if cb is None:
+            return
+        try:
+            cb()
+        except Exception:
+            logger.debug("on_new_message callback error", exc_info=True)
+
     def _reset_segment_state(self, *, preserve_no_edit: bool = False) -> None:
         if preserve_no_edit and self._message_id == "__no_edit__":
             return
@@ -529,6 +548,9 @@ class GatewayStreamConsumer:
                 self._message_id = str(result.message_id)
                 self._already_sent = True
                 self._last_sent_text = text
+                # Fresh content bubble — close off any stale tool bubble
+                # above so the next tool starts a new bubble below.
+                self._notify_new_message()
                 return str(result.message_id)
             else:
                 self._edit_supported = False
@@ -661,6 +683,9 @@ class GatewayStreamConsumer:
             sent_any_chunk = True
             last_successful_chunk = chunk
             last_message_id = result.message_id or last_message_id
+            # Each fallback chunk is a fresh platform message — notify
+            # so any stale tool-progress bubble gets closed off.
+            self._notify_new_message()
 
         self._message_id = last_message_id
         self._already_sent = True
@@ -744,6 +769,11 @@ class GatewayStreamConsumer:
             # tool..."), not the final response. Setting already_sent would cause
             # the final response to be incorrectly suppressed when there are
             # multiple tool calls. See: https://github.com/NousResearch/hermes-agent/issues/10454
+            if result.success:
+                # Commentary counts as fresh content — close off any
+                # stale tool bubble above it so the next tool starts a
+                # new bubble below.
+                self._notify_new_message()
             return result.success
         except Exception as e:
             logger.error("Commentary send error: %s", e)
@@ -973,6 +1003,11 @@ class GatewayStreamConsumer:
                         # every delta/tool boundary when platforms accept a
                         # message but do not return an editable message id.
                         self._message_id = "__no_edit__"
+                    # Notify the gateway that a fresh content bubble was
+                    # created so any accumulated tool-progress bubble above
+                    # gets closed off — the next tool fires into a new
+                    # bubble below, preserving chronological order.
+                    self._notify_new_message()
                     return True
                 else:
                     # Initial send failed — disable streaming for this session