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/maps/nearby_locations.html

@@ -316,6 +316,11 @@
 <!-- Leaflet JS -->
 <script src="https://unpkg.com/leaflet@1.9.4/dist/leaflet.js"></script>
 
+{# Security: Safely embed JSON data using Django's json_script tag to prevent XSS #}
+{% if nearby_locations %}
+{{ nearby_locations|json_script:"nearby-locations-data" }}
+{% endif %}
+
 <script>
 // Nearby locations map class
 class NearbyMap {
@@ -436,11 +441,14 @@ class NearbyMap {
     
     addLocationMarkers() {
         {% if nearby_locations %}
-        const locations = {{ nearby_locations|safe }};
-        
-        locations.forEach(location => {
-            this.addLocationMarker(location);
-        });
+        {# Security: Use json_script to safely embed JSON data without XSS risk #}
+        const locationsData = document.getElementById('nearby-locations-data');
+        if (locationsData) {
+            const locations = JSON.parse(locationsData.textContent);
+            locations.forEach(location => {
+                this.addLocationMarker(location);
+            });
+        }
         {% endif %}
     }