fix(tempo): only log red team execution time, use pre-computed duration

Two bugs fixed:

1. Blue team evaluation was also sent to Tempo. Only operator (red team)
   execution time should be logged — blue team time is tracked internally
   in Aegis but does NOT represent billable operator work. Added a
   whitelist (_TEMPO_ACTIVITY_TYPES = {"red_team_execution"}).

2. _calculate_duration() re-computed duration from red_started_at to
   datetime.utcnow() at call time, without subtracting paused seconds.
   This caused inflated times (e.g. 45 min instead of 5 min) when there
   was any delay between the workflow transition and the Tempo call.
   Now the duration_seconds already computed by _create_phase_worklog
   (gross elapsed - paused) is passed directly to auto_log_test_worklog
   and used as-is, so Aegis and Tempo always agree on the duration.

Also: use red_started_at as the worklog date (not submission timestamp)
so the Tempo entry reflects when the work actually happened.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

backend/app/services/test_workflow_service.py

@@ -327,10 +327,11 @@ def _create_phase_worklog(
             test.id, activity_type, duration_seconds, wl.id,
         )
 
-        # Sync to Tempo if enabled
+        # Sync to Tempo: only red_team_execution, using the already-computed
+        # duration so the Tempo entry is identical to the Aegis worklog.
         try:
             from app.services.tempo_service import auto_log_test_worklog
-            auto_log_test_worklog(db, test, user, activity_type)
+            auto_log_test_worklog(db, test, user, activity_type, duration_seconds)
         except Exception as e:
             logger.warning("Tempo sync failed for worklog: %s", e, exc_info=True)