Restore cancellation checks before report delivery

docs/roadmap/remediation.md

@@ -1,6 +1,6 @@
 # Invocation reporting audit remediation
 
-Status: remediation in progress; 3 of 7 findings complete.
+Status: remediation in progress; 4 of 7 findings complete.
 
 ## Review scope
 
@@ -248,7 +248,15 @@ public exact-wording guarantee.
 
 ## 4. Restore cancellation checks between report preparation and delivery
 
-Priority: P2. Status: open.
+Priority: P2. Status: complete.
+
+- [x] Completed: restored preparation-before-delivery cancellation checks for
+  PromptKit catalogs, definitions, requirements, and validation, and buffered
+  configuration diff/sources/YAML explanation reports. Cancellation retains its
+  operation cause without becoming a rendering failure; native streaming and
+  smoke-report behavior remain unchanged. Controlled preparation/serialization
+  checks cover ordinary and quiet modes. Validation: module suites pass in
+  `integrations/ckconfig` and `integrations/ckprompt`.
 
 ### Finding and evidence