feat: make workflow execution timeout configurable via env var

Adds WORKFLOW_EXECUTION_TIMEOUT_SECONDS so agents whose tasks run
longer than the previous hardcoded 24h cap can extend the timeout
without forking the SDK. Default behavior (24h) is unchanged.

Author: danielmillerp

src/agentex/lib/core/temporal/services/temporal_task_service.py

@@ -1,6 +1,7 @@
 from __future__ import annotations
 
 from typing import Any
+from datetime import timedelta
 
 from agentex.types.task import Task
 from agentex.types.agent import Agent
@@ -41,6 +42,7 @@ async def submit_task(self, agent: Agent, task: Task, params: dict[str, Any] | N
             ),
             id=task.id,
             task_queue=self._env_vars.WORKFLOW_TASK_QUEUE,
+            execution_timeout=timedelta(seconds=self._env_vars.WORKFLOW_EXECUTION_TIMEOUT_SECONDS),
         )
 
     async def get_state(self, task_id: str) -> WorkflowState:

src/agentex/lib/environment_variables.py

@@ -32,6 +32,7 @@ class EnvVarKeys(str, Enum):
     # Workflow Configuration
     WORKFLOW_NAME = "WORKFLOW_NAME"
     WORKFLOW_TASK_QUEUE = "WORKFLOW_TASK_QUEUE"
+    WORKFLOW_EXECUTION_TIMEOUT_SECONDS = "WORKFLOW_EXECUTION_TIMEOUT_SECONDS"
     # Temporal Worker Configuration
     HEALTH_CHECK_PORT = "HEALTH_CHECK_PORT"
     # Auth Configuration
@@ -74,6 +75,10 @@ class EnvironmentVariables(BaseModel):
     # Workflow Configuration
     WORKFLOW_TASK_QUEUE: str | None = None
     WORKFLOW_NAME: str | None = None
+    # Maximum total time (in seconds) a workflow execution can run, including
+    # retries and continue-as-new. Defaults to 24h to bound runaway workflows;
+    # agents with longer-running tasks should override this.
+    WORKFLOW_EXECUTION_TIMEOUT_SECONDS: int = 86400
     # Temporal Worker Configuration
     HEALTH_CHECK_PORT: int = 80
     # Auth Configuration