Add comprehensive API documentation for ThrillWiki integration and features

- Introduced Next.js integration guide for ThrillWiki API, detailing authentication, core domain APIs, data structures, and implementation patterns.
- Documented the migration to Rich Choice Objects, highlighting changes for frontend developers and enhanced metadata availability.
- Fixed the missing `get_by_slug` method in the Ride model, ensuring proper functionality of ride detail endpoints.
- Created a test script to verify manufacturer syncing with ride models, ensuring data integrity across related models.

backend/apps/rides/selectors.py

@@ -8,7 +8,8 @@ from django.db.models import QuerySet, Q, Count, Avg, Prefetch
 from django.contrib.gis.geos import Point
 from django.contrib.gis.measure import Distance
 
-from .models import Ride, RideModel, RideReview, CATEGORY_CHOICES
+from .models import Ride, RideModel, RideReview
+from .choices import RIDE_CATEGORIES
 
 
 def ride_list_for_display(
@@ -275,10 +276,10 @@ def ride_statistics_by_category() -> Dict[str, Any]:
     """
 
     stats = {}
-    for category_code, category_name in CATEGORY_CHOICES:
-        if category_code:  # Skip empty choice
-            count = Ride.objects.filter(category=category_code).count()
-            stats[category_code] = {"name": category_name, "count": count}
+    for category in RIDE_CATEGORIES:
+        if category.value:  # Skip empty choice
+            count = Ride.objects.filter(category=category.value).count()
+            stats[category.value] = {"name": category.label, "count": count}
 
     return stats