fix: propagate DB errors in cancellation checks, remove unimplemented token_budget

- engine.go: don't silently ignore DB errors in cancellation status checks;
  distinguish sql.ErrNoRows from other errors and return them instead of
  silently proceeding with unknown cancellation state
- workflow_connector.go: remove token_budget from docstring (not implemented)
- connectors.md: remove undocumented token_budget param row; add 'cel'
  language specifier to CEL path code fence

Co-authored-by: Michael McNees <michaelmcnees@users.noreply.github.com>

Author: github-actions[bot]

packages/engine/internal/engine/engine.go

@@ -241,12 +241,16 @@ func (e *Engine) resumeExecution(ctx context.Context, execID string, workflowNam
 	for _, step := range wf.Steps {
 		// Check if execution was cancelled externally (e.g., mantle cancel).
 		var currentStatus string
-		if err := e.DB.QueryRowContext(ctx, "SELECT status FROM workflow_executions WHERE id = $1 AND team_id = $2", execID, sc.TeamID).Scan(&currentStatus); err == nil {
-			if currentStatus == "cancelled" {
-				result.Status = "cancelled"
-				result.Error = "execution cancelled"
-				return result, nil
+		if err := e.DB.QueryRowContext(ctx, "SELECT status FROM workflow_executions WHERE id = $1 AND team_id = $2", execID, sc.TeamID).Scan(&currentStatus); err != nil {
+			if errors.Is(err, sql.ErrNoRows) {
+				return nil, fmt.Errorf("execution %s not found", execID)
 			}
+			return nil, fmt.Errorf("checking cancellation status for %s: %w", execID, err)
+		}
+		if currentStatus == "cancelled" {
+			result.Status = "cancelled"
+			result.Error = "execution cancelled"
+			return result, nil
 		}
 
 		// Skip already-completed steps (checkpoint recovery).
@@ -624,7 +628,13 @@ func (e *Engine) executeStepLogic(ctx context.Context, execID string, step workf
 	for attempt := 1; attempt <= maxAttempts; attempt++ {
 		// Check if the execution has been cancelled before each retry attempt.
 		var execStatus string
-		if err := e.DB.QueryRowContext(ctx, "SELECT status FROM workflow_executions WHERE id = $1 AND team_id = $2", execID, sc.TeamID).Scan(&execStatus); err == nil && execStatus == "cancelled" {
+		if err := e.DB.QueryRowContext(ctx, "SELECT status FROM workflow_executions WHERE id = $1 AND team_id = $2", execID, sc.TeamID).Scan(&execStatus); err != nil {
+			if errors.Is(err, sql.ErrNoRows) {
+				return nil, fmt.Errorf("execution %s not found", execID)
+			}
+			return nil, fmt.Errorf("checking cancellation status for %s: %w", execID, err)
+		}
+		if execStatus == "cancelled" {
 			return nil, fmt.Errorf("execution cancelled")
 		}
 

packages/engine/internal/engine/workflow_connector.go

@@ -25,7 +25,6 @@ type WorkflowConnector struct {
 //   - workflow (string, required): name of the child workflow
 //   - version (int, optional): version to run; 0 or omitted = latest
 //   - inputs (map[string]any, optional): input parameters for the child
-//   - token_budget (int64, optional): token budget override for the child
 func (wc *WorkflowConnector) Execute(ctx context.Context, params map[string]any) (map[string]any, error) {
 	// Extract required workflow name.
 	workflowName, ok := params["workflow"].(string)

packages/site/src/content/docs/workflow-reference/connectors.md

@@ -606,7 +606,6 @@ Invokes another workflow as a child execution. The child workflow runs synchrono
 | `workflow` | string | Yes | Name of the child workflow to execute. |
 | `version` | integer | No | Specific version to run. Omit to use the latest applied version. |
 | `inputs` | map | No | Input parameters to pass to the child workflow. |
-| `token_budget` | integer | No | Token budget override for the child execution. |
 
 **Output:**
 
@@ -620,7 +619,7 @@ Invokes another workflow as a child execution. The child workflow runs synchrono
 
 Child step outputs are nested under the parent step's output:
 
-```
+```cel
 steps['my-step'].output.steps['child-step'].output.field
 ```