Add API root endpoint at /api/

Created /api/ endpoint that returns JSON with:
- API status
- Available endpoints
- Version information

This fixes the "Not Found" error when accessing /api/ and
provides a useful API discovery endpoint for clients.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>

config/views.py

@@ -0,0 +1,23 @@
+"""
+API root views for KeepItGoing.
+"""
+
+from django.http import JsonResponse
+
+
+def api_root(request):
+    """
+    API root endpoint - returns available API endpoints.
+    """
+    return JsonResponse({
+        'message': 'KeepItGoing API',
+        'version': '1.0',
+        'endpoints': {
+            'users': '/api/users/',
+            'tasks': '/api/tasks/',
+            'sync': '/api/sync/',
+            'notifications': '/api/notifications/',
+            'admin': '/admin/',
+        },
+        'status': 'running'
+    })