fix: add containerName to reporter frontmatter for cleanup routing

Workflow validation failed because reporter's graph edges reference
{{{containerName}}} but reporter's frontmatter didn't include the field.

.workflows/e2e-check.yaml

@@ -348,6 +348,7 @@ roles:
          ```
 
       4. Collect created issue numbers
+      5. Include the containerName from your input in your frontmatter output (needed for cleanup)
 
     output: "List created issues. Set $status."
     frontmatter:
@@ -358,13 +359,15 @@ roles:
             issues:
               type: array
               items: { type: string }
-          required: [$status, issues]
+            containerName: { type: string }
+          required: [$status, issues, containerName]
         - type: object
           properties:
             $status: { const: "partial" }
             created: { type: number }
             failed: { type: number }
-          required: [$status, created, failed]
+            containerName: { type: string }
+          required: [$status, created, failed, containerName]
 
   cleanup:
     description: "Stops and removes the Docker container"