fix(m7): red write always lands on executed + state pill out of Commentaires

User reported two issues on the scenario table:

1. After filling only red_command + executed_at, the pill read
   "Reviewed" instead of "Awaiting review". Cause: the auto-promotion
   was gated on `state in {pending, skipped, blocked}`, so a test that
   blue had already reviewed stayed in `reviewed_by_blue` after a red
   edit. That contradicts the implicit lifecycle (red modifying a
   reviewed test invalidates the review).
2. The state pill lived inside the Commentaires column, polluting a
   cell meant for blue-team comments.

Fixes
- backend/app/services/mission_tests.py: any red-side write now lands
  the state on `executed` unconditionally (including from
  `reviewed_by_blue`). Same-PUT red+blue still flows
  executed → reviewed_by_blue.
- frontend/src/pages/MissionScenarioTable.tsx: state pill moves from
  CommentairesCell to the Test column (top of the row, above the
  snapshot name + MITRE chips). Commentaires now holds only the
  detection_level pill + blue_comment_md.

Tests
- New pytest: `test_red_write_on_reviewed_reverts_to_executed` —
  reviewed_by_blue + red edit ⇒ executed. 143 pytest green.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

backend/app/services/mission_tests.py

@@ -611,13 +611,17 @@ def update_mission_test_fields(
 
         # Implicit lifecycle (post-amendement 2026-05-15 bis): the explicit
         # workflow is gone from the UI. A write to ANY red field implies the
-        # test was executed (auto-stamp executed_at if the operator didn't
-        # supply one); a write to ANY blue field on an executed test implies
-        # the blue team reviewed it. The /transition endpoint stays for
-        # back-fill but is no longer the primary path.
+        # test was executed AND the review (if any) is potentially stale —
+        # so the state always lands on `executed`, even from `reviewed_by_blue`
+        # (red just changed something, blue needs to re-review). A write to
+        # ANY blue field on an executed test implies the blue team reviewed
+        # it. Note that a same-PUT red+blue (e.g. an admin filling both
+        # sides) flows `* → executed → reviewed_by_blue` and lands on
+        # `reviewed_by_blue`. The /transition endpoint stays for back-fill
+        # but is no longer the primary path.
         red_touched = bool(touched & _RED_FIELDS)
         blue_touched = bool(touched & _BLUE_FIELDS)
-        if red_touched and test.state in {"pending", "skipped", "blocked"}:
+        if red_touched:
             if test.executed_at is None:
                 test.executed_at = datetime.now(tz=timezone.utc)
                 test.executed_at_overridden = False