++ campagne: "In corso" solo per territori assegnati nel periodo

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

app/Models/Campagna.php

@@ -61,12 +61,12 @@ class Campagna extends Model
     }
 
     /**
-     * Assignments still open that were out during this campaign (assigned
-     * on or before its end): they can be counted for it when they come back.
+     * Assignments made during this campaign and not yet returned.
      */
     public function assegnazioniInCorso()
     {
         return Assegnazione::whereNull('returned_at')
+            ->where('assigned_at', '>=', $this->start_date)
             ->where('assigned_at', '<=', $this->end_date);
     }