feat: flush memory before summarization (#2176)

* feat: flush memory before summarization

* fix: keep agent-scoped memory on summarization flush

* fix: harden summarization hook plumbing

* fix: address summarization review feedback

* style: format memory middleware

backend/packages/harness/deerflow/agents/memory/queue.py

@@ -61,48 +61,88 @@ class MemoryUpdateQueue:
             return
 
         with self._lock:
-            existing_context = next(
-                (context for context in self._queue if context.thread_id == thread_id),
-                None,
-            )
-            merged_correction_detected = correction_detected or (existing_context.correction_detected if existing_context is not None else False)
-            merged_reinforcement_detected = reinforcement_detected or (existing_context.reinforcement_detected if existing_context is not None else False)
-            context = ConversationContext(
+            self._enqueue_locked(
                 thread_id=thread_id,
                 messages=messages,
                 agent_name=agent_name,
-                correction_detected=merged_correction_detected,
-                reinforcement_detected=merged_reinforcement_detected,
+                correction_detected=correction_detected,
+                reinforcement_detected=reinforcement_detected,
             )
-
-            # Check if this thread already has a pending update
-            # If so, replace it with the newer one
-            self._queue = [c for c in self._queue if c.thread_id != thread_id]
-            self._queue.append(context)
-
-            # Reset or start the debounce timer
             self._reset_timer()
 
         logger.info("Memory update queued for thread %s, queue size: %d", thread_id, len(self._queue))
 
+    def add_nowait(
+        self,
+        thread_id: str,
+        messages: list[Any],
+        agent_name: str | None = None,
+        correction_detected: bool = False,
+        reinforcement_detected: bool = False,
+    ) -> None:
+        """Add a conversation and start processing immediately in the background."""
+        config = get_memory_config()
+        if not config.enabled:
+            return
+
+        with self._lock:
+            self._enqueue_locked(
+                thread_id=thread_id,
+                messages=messages,
+                agent_name=agent_name,
+                correction_detected=correction_detected,
+                reinforcement_detected=reinforcement_detected,
+            )
+            self._schedule_timer(0)
+
+        logger.info("Memory update queued for immediate processing on thread %s, queue size: %d", thread_id, len(self._queue))
+
+    def _enqueue_locked(
+        self,
+        *,
+        thread_id: str,
+        messages: list[Any],
+        agent_name: str | None,
+        correction_detected: bool,
+        reinforcement_detected: bool,
+    ) -> None:
+        existing_context = next(
+            (context for context in self._queue if context.thread_id == thread_id),
+            None,
+        )
+        merged_correction_detected = correction_detected or (existing_context.correction_detected if existing_context is not None else False)
+        merged_reinforcement_detected = reinforcement_detected or (existing_context.reinforcement_detected if existing_context is not None else False)
+        context = ConversationContext(
+            thread_id=thread_id,
+            messages=messages,
+            agent_name=agent_name,
+            correction_detected=merged_correction_detected,
+            reinforcement_detected=merged_reinforcement_detected,
+        )
+
+        self._queue = [c for c in self._queue if c.thread_id != thread_id]
+        self._queue.append(context)
+
     def _reset_timer(self) -> None:
         """Reset the debounce timer."""
         config = get_memory_config()
+        self._schedule_timer(config.debounce_seconds)
 
+        logger.debug("Memory update timer set for %ss", config.debounce_seconds)
+
+    def _schedule_timer(self, delay_seconds: float) -> None:
+        """Schedule queue processing after the provided delay."""
         # Cancel existing timer if any
         if self._timer is not None:
             self._timer.cancel()
 
-        # Start new timer
         self._timer = threading.Timer(
-            config.debounce_seconds,
+            delay_seconds,
             self._process_queue,
         )
         self._timer.daemon = True
         self._timer.start()
 
-        logger.debug("Memory update timer set for %ss", config.debounce_seconds)
-
     def _process_queue(self) -> None:
         """Process all queued conversation contexts."""
         # Import here to avoid circular dependency
@@ -110,8 +150,8 @@ class MemoryUpdateQueue:
 
         with self._lock:
             if self._processing:
-                # Already processing, reschedule
-                self._reset_timer()
+                # Preserve immediate flush semantics even if another worker is active.
+                self._schedule_timer(0)
                 return
 
             if not self._queue:
@@ -164,6 +204,13 @@ class MemoryUpdateQueue:
 
         self._process_queue()
 
+    def flush_nowait(self) -> None:
+        """Start queue processing immediately in a background thread."""
+        with self._lock:
+            # Daemon thread: queued messages may be lost if the process exits
+            # before _process_queue completes. Acceptable for best-effort memory updates.
+            self._schedule_timer(0)
+
     def clear(self) -> None:
         """Clear the queue without processing.