Close completed watcher groups when the next category starts

- update the categorized watcher to mark a grouped subrun complete once its final check-xml-files.ts artifact exists and the next active host belongs to a different inferred group
- prevent a finished group such as ubuntu from being kept in RUNNING state after execution has already advanced into the next category
- allow grouped Mattermost posts to be emitted at category boundaries instead of being blocked by stale active-group carryover

atvm/watcher-service/atvm_run_watcher.py

@@ -805,6 +805,8 @@ def discover_categorized_subruns(
 ) -> List[Dict[str, object]]:
     xml_dir = reporter_root / "xml"
     current_subrun_build = extract_active_subrun_build(build_name)
+    current_active_host = find_current_running_host(log_text, [])
+    current_active_group = infer_group_from_host(current_active_host) if current_active_host else None
     expected_hosts = extract_expected_hosts(log_text)
     completed_summaries = extract_completed_subrun_summaries(log_text, inventory)
     merged_subrun_states: Dict[str, Dict[str, object]] = {}
@@ -848,13 +850,19 @@ def discover_categorized_subruns(
             if summary:
                 current_summary_index += 1
             state = "RUNNING"
+            display_name = corrected_categorized_display_name(raw_display_name, list(host_results))
+            display_group = None
+            display_group_match = re.search(r"-(amazonlinux|centos|ubuntu|rocky|redhat|oracle|fedora|debian|suse|windows)-batch", display_name)
+            if display_group_match:
+                display_group = display_group_match.group(1)
             if cancelled:
                 state = "CANCELLED"
             elif check_ts and not host_results and parent_active:
                 state = "RUNNING"
+            elif check_ts and display_group and current_active_group and display_group != current_active_group:
+                state = "FAILED" if any(result.failures for result in host_results.values()) else "COMPLETED"
             elif check_ts or raw_display_name != current_subrun_build or not parent_active:
                 state = "FAILED" if any(result.failures for result in host_results.values()) else "COMPLETED"
-            display_name = corrected_categorized_display_name(raw_display_name, list(host_results))
             notes = [f"Categorized sub-run discovered from reporter file `{xml_path.name}`."]
             if check_ts:
                 notes.append("Final `check-xml-files.ts` validation passed.")