feat(tests): archive round history on reopen, stop pausing from setting Jira On Hold

- Reopening a test for rework (red or blue) now archives the round that's
  ending into a new test_round_history table before resetting the live
  fields — procedure/results/detection data is preserved instead of
  overwritten, and Phase Timeline renders every past round alongside the
  current one, so Blue Team keeps visibility into earlier Red attempts.
- Each archived round also posts a permanent Jira comment (push_round_archived)
  since Jira's custom fields only ever show the latest value once the next
  round resubmits — the comment thread is what preserves full history there.
- push_pause_event no longer transitions the Jira issue to "On Hold" — a
  timer pause is not a real Hold, and flipping Jira status for it was
  misleading. Only the explicit Hold action (push_hold_event) does that now.

backend/app/services/test_crud_service.py

@@ -393,7 +393,10 @@ def get_test_detail(db: Session, test_id: uuid.UUID) -> Test:
     # Assign test = (
     test = (
         db.query(Test)
-        .options(joinedload(Test.evidences), joinedload(Test.technique))
+        .options(
+            joinedload(Test.evidences), joinedload(Test.technique),
+            joinedload(Test.round_history),
+        )
         .filter(Test.id == test_id)
         # Chain .first() call
         .first()