always generate migration report. use subagents with multiple workloads.

Author: alexnastetsky

skills/databricks-serverless-migration/SKILL.md

@@ -623,6 +623,14 @@ Submission is optional and opt-in. We use reports to prioritize new patterns and
 
 **Never transmit the report automatically.** The user owns their data and must review before sharing.
 
+## Success report
+
+If the migration was successful, generate a report as well, using similar methods. For each workload migrated, show what was done.
+
+## Multiple workload migration
+
+When migrating multiple workloads in one session, parallelize this work as much as possible to migrate multiple workloads in parallel, including using subagents.
+
 ## Reference Guides
 
 For detailed workarounds and code examples beyond the quick fixes above: