feat(favorites): add EventLike model, favorites API, and notifications module

- EventLike model (user × event unique constraint, indexed)
- contributed_by field on Event (EVT ID or email of community contributor)
- Favorites API endpoints: toggle-like, my-likes, my-liked-events
- Notifications app wired into main urls.py at /api/notifications/
- accounts migration 0014_merge_0013 (resolves split 0013 branches)
- requirements.txt updated

events/migrations/0011_event_contributed_by.py

@@ -0,0 +1,73 @@
+"""
+Add contributed_by field to Event and backfill from overloaded source field.
+
+The admin dashboard stores community contributor identifiers (EVT-XXXXXXXX or email)
+in the source field. This migration:
+1. Adds a dedicated contributed_by CharField
+2. Copies user identifiers from source → contributed_by
+3. Normalizes source back to its intended choices ('eventify', 'community', 'partner')
+"""
+
+from django.db import migrations, models
+
+
+def backfill_contributed_by(apps, schema_editor):
+    """Move user identifiers from source to contributed_by."""
+    Event = apps.get_model('events', 'Event')
+
+    STANDARD_SOURCES = {'eventify', 'community', 'partner', 'eventify_team', 'official', ''}
+
+    for event in Event.objects.all().iterator():
+        source_val = (event.source or '').strip()
+        changed = False
+
+        # User identifier: contains @ (email) or starts with EVT- (eventifyId)
+        if source_val and source_val not in STANDARD_SOURCES and not source_val.startswith('partner:'):
+            event.contributed_by = source_val
+            event.source = 'community'
+            changed = True
+
+        # Normalize eventify_team → eventify
+        elif source_val == 'eventify_team':
+            event.source = 'eventify'
+            changed = True
+
+        # Normalize official → eventify
+        elif source_val == 'official':
+            event.source = 'eventify'
+            changed = True
+
+        if changed:
+            event.save(update_fields=['source', 'contributed_by'])
+
+
+def reverse_backfill(apps, schema_editor):
+    """Reverse: move contributed_by back to source."""
+    Event = apps.get_model('events', 'Event')
+    for event in Event.objects.exclude(contributed_by__isnull=True).exclude(contributed_by='').iterator():
+        event.source = event.contributed_by
+        event.contributed_by = None
+        event.save(update_fields=['source', 'contributed_by'])
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('events', '0010_merge_20260324_1443'),
+    ]
+
+    operations = [
+        # Step 1: Add the field
+        migrations.AddField(
+            model_name='event',
+            name='contributed_by',
+            field=models.CharField(
+                blank=True,
+                help_text='Eventify ID (EVT-XXXXXXXX) or email of the community contributor',
+                max_length=100,
+                null=True,
+            ),
+        ),
+        # Step 2: Backfill data
+        migrations.RunPython(backfill_contributed_by, reverse_backfill),
+    ]

events/migrations/0012_eventlike.py

@@ -0,0 +1,38 @@
+from django.conf import settings
+from django.db import migrations, models
+import django.db.models.deletion
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('events', '0011_event_contributed_by'),
+        migrations.swappable_dependency(settings.AUTH_USER_MODEL),
+    ]
+
+    operations = [
+        migrations.CreateModel(
+            name='EventLike',
+            fields=[
+                ('id', models.BigAutoField(auto_created=True, primary_key=True, serialize=False, verbose_name='ID')),
+                ('created_at', models.DateTimeField(auto_now_add=True)),
+                ('event', models.ForeignKey(
+                    on_delete=django.db.models.deletion.CASCADE,
+                    related_name='likes',
+                    to='events.event',
+                )),
+                ('user', models.ForeignKey(
+                    on_delete=django.db.models.deletion.CASCADE,
+                    related_name='event_likes',
+                    to=settings.AUTH_USER_MODEL,
+                )),
+            ],
+            options={
+                'unique_together': {('user', 'event')},
+            },
+        ),
+        migrations.AddIndex(
+            model_name='eventlike',
+            index=models.Index(fields=['user', '-created_at'], name='events_even_user_id_created_idx'),
+        ),
+    ]

events/models.py

@@ -58,6 +58,11 @@ class Event(models.Model):
     is_featured = models.BooleanField(default=False, help_text='Show this event in the featured section')
     is_top_event = models.BooleanField(default=False, help_text='Show this event in the Top Events section')
 
+    contributed_by = models.CharField(
+        max_length=100, blank=True, null=True,
+        help_text='Eventify ID (EVT-XXXXXXXX) or email of the community contributor',
+    )
+
     def __str__(self):
         return f"{self.name} ({self.start_date})"
 
@@ -71,3 +76,26 @@ class EventImages(models.Model):
         return f"{self.event_image}"
 
 
+class EventLike(models.Model):
+    user = models.ForeignKey(
+        'accounts.User',
+        on_delete=models.CASCADE,
+        related_name='event_likes'
+    )
+    event = models.ForeignKey(
+        Event,
+        on_delete=models.CASCADE,
+        related_name='likes'
+    )
+    created_at = models.DateTimeField(auto_now_add=True)
+
+    class Meta:
+        unique_together = ('user', 'event')
+        indexes = [
+            models.Index(fields=['user', '-created_at']),
+        ]
+
+    def __str__(self):
+        return f"{self.user.email} likes {self.event.name}"
+
+