fix: scheduler next_run accounts for elapsed time since last cycle

On restart the scheduler was counting interval_hours from now, ignoring
when the last cycle actually ran. It now reads last_run_at (in-memory or
DB) and deducts elapsed time so a restart doesn't silently push the next
fire by a full interval.

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

backend/services/auto_cycle.py

@@ -1870,11 +1870,30 @@ def _scheduler_loop(stop_event: threading.Event):
             _current_status["interval_hours"] = interval_hours
             logger.info(f"[Scheduler] Weekend — prochain cycle à {next_slot.strftime('%H:%M')} UTC ({wait_secs/3600:.1f}h)")
         else:
-            wait_secs = interval_hours * 3600
-            next_run = now_utc + timedelta(hours=interval_hours)
+            # Account for time already elapsed since last cycle so a restart
+            # doesn't reset the countdown — fire as soon as the interval is due.
+            last_run_iso = _current_status.get("last_run_at")
+            if not last_run_iso:
+                # Also check DB for the most recent completed run
+                try:
+                    from services.database import get_cycle_runs
+                    recent = get_cycle_runs(limit=1)
+                    if recent:
+                        last_run_iso = recent[0].get("created_at") or recent[0].get("run_id", "")[:19].replace("T", " ")
+                except Exception:
+                    pass
+            elapsed_secs = 0.0
+            if last_run_iso:
+                try:
+                    last_dt = datetime.fromisoformat(last_run_iso.replace(" ", "T").rstrip("Z"))
+                    elapsed_secs = (now_utc - last_dt).total_seconds()
+                except Exception:
+                    pass
+            wait_secs = max(60, interval_hours * 3600 - elapsed_secs)
+            next_run = now_utc + timedelta(seconds=wait_secs)
             _current_status["next_run_at"] = next_run.isoformat()
             _current_status["interval_hours"] = interval_hours
-            logger.info(f"[Scheduler] Prochain cycle dans {interval_hours}h ({next_run.strftime('%H:%M')} UTC)")
+            logger.info(f"[Scheduler] Prochain cycle dans {wait_secs/3600:.1f}h ({next_run.strftime('%H:%M')} UTC) — elapsed since last: {elapsed_secs/3600:.1f}h")
 
         stop_event.wait(timeout=wait_secs)