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/admin.py

@@ -197,9 +197,11 @@ class RideAdmin(admin.ModelAdmin):
     @admin.display(description="Category")
     def category_display(self, obj):
         """Display category with full name"""
-        return dict(obj._meta.get_field("category").choices).get(
-            obj.category, obj.category
-        )
+        choices_dict = dict(obj._meta.get_field("category").choices)
+        if obj.category in choices_dict:
+            return choices_dict[obj.category]
+        else:
+            raise ValueError(f"Unknown category: {obj.category}")
 
 
 @admin.register(RideModel)
@@ -240,9 +242,11 @@ class RideModelAdmin(admin.ModelAdmin):
     @admin.display(description="Category")
     def category_display(self, obj):
         """Display category with full name"""
-        return dict(obj._meta.get_field("category").choices).get(
-            obj.category, obj.category
-        )
+        choices_dict = dict(obj._meta.get_field("category").choices)
+        if obj.category in choices_dict:
+            return choices_dict[obj.category]
+        else:
+            raise ValueError(f"Unknown category: {obj.category}")
 
     @admin.display(description="Installations")
     def ride_count(self, obj):