Fix step exit code references in examples

writing-workflows/continue-on.md

@@ -212,7 +212,7 @@ steps:
   - id: fallback_method
     run: echo "Processing with fallback settings"
     preconditions:
-      - condition: "${env.TRY_OPTIMAL_METHOD_EXIT_CODE}"
+      - condition: "${try_optimal_method.exit_code}"
         expected: "re:[1-9][0-9]*"  # Only run if previous failed
     depends: try_optimal_method
 ```
@@ -345,7 +345,7 @@ steps:
   - id: check_secondary
     run: curl -f https://secondary.example.com/health
     preconditions:
-      - condition: "${env.CHECK_PRIMARY_EXIT_CODE}"
+      - condition: "${check_primary.exit_code}"
         expected: "re:[1-9][0-9]*"  # Only if primary failed
     depends: check_primary
 ```

writing-workflows/control-flow.md

@@ -1013,7 +1013,7 @@ steps:
   - id: simple_method
     run: echo "Processing with simple settings"
     preconditions:
-      - condition: "${env.TRY_ADVANCED_METHOD_EXIT_CODE}"
+      - condition: "${try_advanced_method.exit_code}"
         expected: "re:[1-9][0-9]*"
     depends: try_advanced_method
 

writing-workflows/queues.md

@@ -67,4 +67,4 @@ steps:
 
 `with.queue` overrides the child DAG's queue for that enqueued run. If it is omitted, Dagu uses the child DAG's top-level `queue`, the base-config default, or the child's local queue. The parent step succeeds after the child run is persisted and added to the queue.
 
-Use `action: dag.run` instead when the parent workflow must wait for the child DAG result before continuing.
+Use `action: dag.run` instead when the parent workflow must wait for the child DAG result before continuing. A `dag.run` child starts directly rather than through its queue, so the queue's `max_concurrency` does not limit it.