fix and adjust main dashboard ai insight

backend/apps/operations/models.py

@@ -27,15 +27,6 @@ class IotPanel(models.Model):
 
 
 class AIInsight(models.Model):
-    SOURCE_GENERATED = "generated"
-    SOURCE_CACHE = "cache"
-    SOURCE_LOCAL_FALLBACK = "local_fallback"
-    SOURCE_CHOICES = [
-        (SOURCE_GENERATED, "Generated"),
-        (SOURCE_CACHE, "Cache"),
-        (SOURCE_LOCAL_FALLBACK, "Local fallback"),
-    ]
-
     date = models.DateField()
     insight_text = models.TextField()
     alert = models.CharField(max_length=100, blank=True, default="")
@@ -50,12 +41,6 @@ class AIInsight(models.Model):
     topic = models.CharField(max_length=64, blank=True, default="", db_index=True)
     report_type = models.CharField(max_length=32, blank=True, default="page", db_index=True)
     report_period = models.CharField(max_length=64, blank=True, default="current", db_index=True)
-    source = models.CharField(
-        max_length=32,
-        choices=SOURCE_CHOICES,
-        default=SOURCE_GENERATED,
-        blank=True,
-    )
     summary = models.TextField(blank=True, default="")
     citations = models.TextField(blank=True, default="[]")
     created_at = models.DateTimeField(auto_now_add=True)