fix: route memory provider tools in sequential execution path (#4803)

Memory provider tools (hindsight_retain, honcho_search, etc.) were
advertised to the model via tool schemas but failed with 'Unknown tool'
at execution time. The concurrent path (_invoke_tool) correctly checks
self._memory_manager.has_tool() before falling through to the registry,
but the sequential path (_execute_tool_calls_sequential) was never
updated with this check. Since sequential is the default for single
tool calls, memory provider tools always hit the registry dispatcher
which returns 'Unknown tool' because they're not registered there.

Add the memory_manager dispatch check between the delegate_task handler
and the quiet_mode fallthrough in the sequential path, with proper
spinner/display handling to match the existing pattern.

Reported by KiBenderOP — all memory providers affected (Honcho,
Hindsight, Holographic, etc.).

run_agent.py

@@ -6009,6 +6009,30 @@ class AIAgent:
                         spinner.stop(cute_msg)
                     elif self.quiet_mode:
                         self._vprint(f"  {cute_msg}")
+            elif self._memory_manager and self._memory_manager.has_tool(function_name):
+                # Memory provider tools (hindsight_retain, honcho_search, etc.)
+                # These are not in the tool registry — route through MemoryManager.
+                spinner = None
+                if self.quiet_mode and not self.tool_progress_callback:
+                    face = random.choice(KawaiiSpinner.KAWAII_WAITING)
+                    emoji = _get_tool_emoji(function_name)
+                    preview = _build_tool_preview(function_name, function_args) or function_name
+                    spinner = KawaiiSpinner(f"{face} {emoji} {preview}", spinner_type='dots', print_fn=self._print_fn)
+                    spinner.start()
+                _mem_result = None
+                try:
+                    function_result = self._memory_manager.handle_tool_call(function_name, function_args)
+                    _mem_result = function_result
+                except Exception as tool_error:
+                    function_result = json.dumps({"error": f"Memory tool '{function_name}' failed: {tool_error}"})
+                    logger.error("memory_manager.handle_tool_call raised for %s: %s", function_name, tool_error, exc_info=True)
+                finally:
+                    tool_duration = time.time() - tool_start_time
+                    cute_msg = _get_cute_tool_message_impl(function_name, function_args, tool_duration, result=_mem_result)
+                    if spinner:
+                        spinner.stop(cute_msg)
+                    elif self.quiet_mode:
+                        self._vprint(f"  {cute_msg}")
             elif self.quiet_mode:
                 spinner = None
                 if not self.tool_progress_callback: