feat(leads): add Lead Manager module with full admin and consumer endpoints

- Lead model in admin_api with status/priority/source/assigned_to fields
- Admin API: metrics, list, detail, update views at /api/v1/leads/
- Consumer API: public ScheduleCallView at /api/leads/schedule-call/
- RBAC: 'leads' module registered in ALL_MODULES and StaffProfile scopes
- Migration 0003_lead with indexes on status, priority, created_at, email

admin_api/models.py

@@ -130,7 +130,7 @@ class StaffProfile(models.Model):
     def get_allowed_modules(self):
         scopes = self.get_effective_scopes()
         if '*' in scopes:
-            return ['dashboard', 'partners', 'events', 'ad-control', 'users', 'reviews', 'contributions', 'financials', 'settings']
+            return ['dashboard', 'partners', 'events', 'ad-control', 'users', 'reviews', 'contributions', 'leads', 'financials', 'settings']
         SCOPE_TO_MODULE = {
             'users': 'users',
             'events': 'events',
@@ -140,6 +140,7 @@ class StaffProfile(models.Model):
             'settings': 'settings',
             'ads': 'ad-control',
             'contributions': 'contributions',
+            'leads': 'leads',
         }
         modules = {'dashboard'}
         for scope in scopes:
@@ -181,3 +182,61 @@ class AuditLog(models.Model):
 
     def __str__(self):
         return f"{self.action} by {self.user} at {self.created_at}"
+
+
+# ---------------------------------------------------------------------------
+# Lead Manager
+# ---------------------------------------------------------------------------
+
+class Lead(models.Model):
+    EVENT_TYPE_CHOICES = [
+        ('private', 'Private Event'),
+        ('ticketed', 'Ticketed Event'),
+        ('corporate', 'Corporate Event'),
+        ('wedding', 'Wedding'),
+        ('other', 'Other'),
+    ]
+    STATUS_CHOICES = [
+        ('new', 'New'),
+        ('contacted', 'Contacted'),
+        ('qualified', 'Qualified'),
+        ('converted', 'Converted'),
+        ('closed', 'Closed'),
+    ]
+    SOURCE_CHOICES = [
+        ('schedule_call', 'Schedule a Call'),
+        ('website', 'Website'),
+        ('manual', 'Manual'),
+    ]
+    PRIORITY_CHOICES = [
+        ('low', 'Low'),
+        ('medium', 'Medium'),
+        ('high', 'High'),
+    ]
+
+    name        = models.CharField(max_length=200)
+    email       = models.EmailField()
+    phone       = models.CharField(max_length=20)
+    event_type  = models.CharField(max_length=20, choices=EVENT_TYPE_CHOICES, default='private')
+    message     = models.TextField(blank=True, default='')
+    status      = models.CharField(max_length=20, choices=STATUS_CHOICES, default='new')
+    source      = models.CharField(max_length=20, choices=SOURCE_CHOICES, default='schedule_call')
+    priority    = models.CharField(max_length=10, choices=PRIORITY_CHOICES, default='medium')
+    assigned_to = models.ForeignKey(
+        User, on_delete=models.SET_NULL, null=True, blank=True, related_name='assigned_leads'
+    )
+    notes       = models.TextField(blank=True, default='')
+    created_at  = models.DateTimeField(auto_now_add=True)
+    updated_at  = models.DateTimeField(auto_now=True)
+
+    class Meta:
+        ordering = ['-created_at']
+        indexes  = [
+            models.Index(fields=['status']),
+            models.Index(fields=['priority']),
+            models.Index(fields=['created_at']),
+            models.Index(fields=['email']),
+        ]
+
+    def __str__(self):
+        return f'Lead #{self.pk} — {self.name} ({self.status})'