Improve image handling, optimize hooks, and add rate limiting

This commit introduces several improvements:
- Enhances `RideModelCard` by safely accessing and displaying ride count and image data, preventing potential errors.
- Refactors `useEntityVersions` and `useSearch` hooks to use `useCallback` and improve performance and prevent race conditions.
- Introduces a `MAX_MAP_SIZE` and cleanup mechanism for the rate limiting map in `detect-location` Supabase function to prevent memory leaks.
- Adds robust error handling and cleanup for image uploads in `uploadPendingImages`.
- Modifies `ManufacturerModels` to correctly map and display ride counts.
- Includes error handling for topological sort in `process-selective-approval` Supabase function.

Replit-Commit-Author: Agent
Replit-Commit-Session-Id: 39bb006b-d046-477f-a1f9-b7821836f3a1
Replit-Commit-Checkpoint-Type: intermediate_checkpoint

src/hooks/useUsernameValidation.ts

@@ -1,4 +1,4 @@
-import { useState, useEffect } from 'react';
+import { useState, useEffect, useCallback } from 'react';
 import { supabase } from '@/integrations/supabase/client';
 import { usernameSchema } from '@/lib/validation';
 import { useDebounce } from './useDebounce';
@@ -20,6 +20,33 @@ export function useUsernameValidation(username: string, currentUsername?: string
 
   const debouncedUsername = useDebounce(username, 500);
 
+  const checkUsernameAvailability = useCallback(async (normalizedUsername: string) => {
+    try {
+      const { data, error } = await supabase
+        .from('profiles')
+        .select('username')
+        .eq('username', normalizedUsername)
+        .maybeSingle();
+
+      if (error) throw error;
+
+      const isAvailable = !data;
+      setState({
+        isValid: isAvailable,
+        isAvailable,
+        isChecking: false,
+        error: isAvailable ? null : 'Username is already taken',
+      });
+    } catch (error) {
+      setState({
+        isValid: false,
+        isAvailable: null,
+        isChecking: false,
+        error: 'Error checking username availability',
+      });
+    }
+  }, []);
+
   useEffect(() => {
     if (!debouncedUsername || debouncedUsername === currentUsername) {
       setState({
@@ -47,34 +74,7 @@ export function useUsernameValidation(username: string, currentUsername?: string
     setState(prev => ({ ...prev, isChecking: true, error: null }));
     
     checkUsernameAvailability(validation.data);
-  }, [debouncedUsername, currentUsername]);
-
-  const checkUsernameAvailability = async (normalizedUsername: string) => {
-    try {
-      const { data, error } = await supabase
-        .from('profiles')
-        .select('username')
-        .eq('username', normalizedUsername)
-        .maybeSingle();
-
-      if (error) throw error;
-
-      const isAvailable = !data;
-      setState({
-        isValid: isAvailable,
-        isAvailable,
-        isChecking: false,
-        error: isAvailable ? null : 'Username is already taken',
-      });
-    } catch (error) {
-      setState({
-        isValid: false,
-        isAvailable: null,
-        isChecking: false,
-        error: 'Error checking username availability',
-      });
-    }
-  };
+  }, [debouncedUsername, currentUsername, checkUsernameAvailability]);
 
   return state;
 }