fix(bus): preserve legacy outbound metadata events

nanobot/bus/outbound_events.py

@@ -103,7 +103,9 @@ def outbound_message_for_event(
 def outbound_event_from_message(msg: OutboundMessage) -> OutboundEvent | None:
     """Return the typed outbound event carried by *msg*, if any."""
 
-    return msg.event
+    if msg.event is not None:
+        return msg.event
+    return _legacy_event_from_metadata(msg)
 
 
 def replace_outbound_event(
@@ -125,3 +127,100 @@ def _event_content(event: OutboundEvent) -> str:
     if isinstance(event, ProgressEvent | RetryWaitEvent | StreamDeltaEvent | StreamEndEvent):
         return event.content
     return ""
+
+
+def _legacy_event_from_metadata(msg: OutboundMessage) -> OutboundEvent | None:
+    """Bridge pre-typed outbound metadata flags into typed events.
+
+    New code should set ``OutboundMessage.event`` directly. The fallback keeps
+    older in-process extensions and channel plugins from losing runtime events
+    while they migrate off reserved metadata flags.
+    """
+
+    meta = msg.metadata or {}
+    if meta.get("_runtime_model_updated"):
+        return RuntimeModelUpdatedEvent(
+            model=_metadata_str(meta, "model"),
+            model_preset=_metadata_str(meta, "model_preset"),
+        )
+    if meta.get("_goal_state_sync"):
+        goal_state = meta.get("goal_state")
+        return GoalStateSyncEvent(goal_state if isinstance(goal_state, dict) else {"active": False})
+    if meta.get("_goal_status"):
+        status = meta.get("goal_status")
+        if not isinstance(status, str) or not status:
+            return None
+        return GoalStatusEvent(
+            status=status,
+            started_at=_metadata_float(meta, "started_at", "goal_started_at"),
+        )
+    if meta.get("_turn_end"):
+        goal_state = meta.get("goal_state")
+        return TurnEndEvent(
+            latency_ms=_metadata_int(meta, "latency_ms"),
+            goal_state=goal_state if isinstance(goal_state, dict) else None,
+        )
+    if meta.get("_session_updated"):
+        return SessionUpdatedEvent(scope=_metadata_str(meta, "_session_update_scope"))
+    if meta.get("_retry_wait"):
+        return RetryWaitEvent(content=msg.content)
+    if meta.get("_stream_end"):
+        return StreamEndEvent(
+            content=msg.content,
+            stream_id=_metadata_str(meta, "_stream_id"),
+            resuming=bool(meta.get("_resuming")),
+        )
+    if meta.get("_stream_delta"):
+        return StreamDeltaEvent(
+            content=msg.content,
+            stream_id=_metadata_str(meta, "_stream_id"),
+        )
+    if meta.get("_streamed"):
+        return StreamedResponseEvent()
+    if (
+        meta.get("_progress")
+        or meta.get("_reasoning_delta")
+        or meta.get("_reasoning_end")
+        or meta.get("_reasoning")
+        or meta.get("_file_edit_events")
+        or meta.get("_tool_events")
+    ):
+        tool_events = meta.get("_tool_events")
+        file_edit_events = meta.get("_file_edit_events")
+        return ProgressEvent(
+            content=msg.content,
+            tool_hint=bool(meta.get("_tool_hint")),
+            reasoning=bool(meta.get("_reasoning")),
+            reasoning_delta=bool(meta.get("_reasoning_delta")),
+            reasoning_end=bool(meta.get("_reasoning_end")),
+            stream_id=_metadata_str(meta, "_stream_id"),
+            tool_events=tool_events if isinstance(tool_events, list) else None,
+            file_edit_events=file_edit_events if isinstance(file_edit_events, list) else None,
+        )
+    return None
+
+
+def _metadata_str(meta: Mapping[str, Any], key: str) -> str | None:
+    value = meta.get(key)
+    return value if isinstance(value, str) and value else None
+
+
+def _metadata_int(meta: Mapping[str, Any], key: str) -> int | None:
+    value = meta.get(key)
+    if isinstance(value, bool):
+        return None
+    if isinstance(value, int):
+        return value
+    if isinstance(value, float) and value.is_integer():
+        return int(value)
+    return None
+
+
+def _metadata_float(meta: Mapping[str, Any], *keys: str) -> float | None:
+    for key in keys:
+        value = meta.get(key)
+        if isinstance(value, bool):
+            continue
+        if isinstance(value, int | float):
+            return float(value)
+    return None