feat: Refactor rides app with unique constraints, mixins, and enhanced documentation

- Added migration to convert unique_together constraints to UniqueConstraint for RideModel.
- Introduced RideFormMixin for handling entity suggestions in ride forms.
- Created comprehensive code standards documentation outlining formatting, docstring requirements, complexity guidelines, and testing requirements.
- Established error handling guidelines with a structured exception hierarchy and best practices for API and view error handling.
- Documented view pattern guidelines, emphasizing the use of CBVs, FBVs, and ViewSets with examples.
- Implemented a benchmarking script for query performance analysis and optimization.
- Developed security documentation detailing measures, configurations, and a security checklist.
- Compiled a database optimization guide covering indexing strategies, query optimization patterns, and computed fields.

backend/templates/components/ui/card.html

@@ -1,7 +1,10 @@
 {% comment %}
 Card Component - Django Template Version of shadcn/ui Card
 Usage: {% include 'components/ui/card.html' with title='Card Title' content='Card content' %}
+
+Security: All content variables are sanitized to prevent XSS attacks.
 {% endcomment %}
+{% load safe_html %}
 
 <div class="rounded-lg border bg-card text-card-foreground shadow-sm {{ class|default:'' }}">
   {% if title or header_content %}
@@ -13,25 +16,25 @@ Usage: {% include 'components/ui/card.html' with title='Card Title' content='Car
     <p class="text-sm text-muted-foreground">{{ description }}</p>
     {% endif %}
     {% if header_content %}
-    {{ header_content|safe }}
+    {{ header_content|sanitize }}
     {% endif %}
   </div>
   {% endif %}
-  
+
   {% if content or body_content %}
   <div class="p-6 pt-0">
     {% if content %}
-    {{ content|safe }}
+    {{ content|sanitize }}
     {% endif %}
     {% if body_content %}
-    {{ body_content|safe }}
+    {{ body_content|sanitize }}
     {% endif %}
   </div>
   {% endif %}
-  
+
   {% if footer_content %}
   <div class="flex items-center p-6 pt-0">
-    {{ footer_content|safe }}
+    {{ footer_content|sanitize }}
   </div>
   {% endif %}
 </div>