refactor: move execution limits from engine core to layer

Remove max_execution_time and max_execution_steps from ExecutionContext and GraphEngine since these limits are now handled by ExecutionLimitsLayer. This follows the separation of concerns principle by keeping execution limits as a cross-cutting concern handled by layers rather than embedded in core engine components.

Changes:
- Remove max_execution_time and max_execution_steps from ExecutionContext
- Remove these parameters from GraphEngine.__init__()
- Remove max_execution_time from Dispatcher
- Update workflow_entry.py to no longer pass these parameters
- Update all tests to remove these parameters

api/core/workflow/graph_engine/domain/execution_context.py

@@ -24,14 +24,8 @@ class ExecutionContext:
     user_from: UserFrom
     invoke_from: InvokeFrom
     call_depth: int
-    max_execution_steps: int
-    max_execution_time: int
 
     def __post_init__(self) -> None:
         """Validate execution context parameters."""
         if self.call_depth < 0:
             raise ValueError("Call depth must be non-negative")
-        if self.max_execution_steps <= 0:
-            raise ValueError("Max execution steps must be positive")
-        if self.max_execution_time <= 0:
-            raise ValueError("Max execution time must be positive")

api/core/workflow/graph_engine/graph_engine.py

@@ -65,8 +65,6 @@ class GraphEngine:
         graph: Graph,
         graph_config: Mapping[str, object],
         graph_runtime_state: GraphRuntimeState,
-        max_execution_steps: int,
-        max_execution_time: int,
         command_channel: CommandChannel,
         min_workers: int | None = None,
         max_workers: int | None = None,
@@ -85,8 +83,6 @@ class GraphEngine:
             user_from=user_from,
             invoke_from=invoke_from,
             call_depth=call_depth,
-            max_execution_steps=max_execution_steps,
-            max_execution_time=max_execution_time,
         )
 
         # Graph execution tracks the overall execution state
@@ -216,7 +212,6 @@ class GraphEngine:
             event_handler=self._event_handler_registry,
             event_collector=self._event_manager,
             execution_coordinator=self._execution_coordinator,
-            max_execution_time=self._execution_context.max_execution_time,
             event_emitter=self._event_manager,
         )
 

api/core/workflow/graph_engine/orchestration/dispatcher.py

@@ -34,7 +34,6 @@ class Dispatcher:
         event_handler: "EventHandler",
         event_collector: EventManager,
         execution_coordinator: ExecutionCoordinator,
-        max_execution_time: int,
         event_emitter: EventManager | None = None,
     ) -> None:
         """
@@ -45,14 +44,12 @@ class Dispatcher:
             event_handler: Event handler registry for processing events
             event_collector: Event manager for collecting unhandled events
             execution_coordinator: Coordinator for execution flow
-            max_execution_time: Maximum execution time in seconds
             event_emitter: Optional event manager to signal completion
         """
         self._event_queue = event_queue
         self._event_handler = event_handler
         self._event_collector = event_collector
         self._execution_coordinator = execution_coordinator
-        self._max_execution_time = max_execution_time
         self._event_emitter = event_emitter
 
         self._thread: threading.Thread | None = None