fix: Implement frontend IP lookup to get accurate user location

[roncodes]

Problem

The current whois/IP lookup implementation has a critical bug: it retrieves the server's IP address instead of the user's IP address, resulting in incorrect geolocation data during onboarding.

Example: User in New York → Server in Frankfurt → Onboarding shows Frankfurt, Germany ❌

Root Cause

• Backend uses request()->ip() which returns server IP when behind proxy/load balancer
• Frontend calls backend endpoint, inheriting the same problem
• This affects onboarding city/country pre-fill and language detection

Solution

This PR implements frontend IP lookup using free geolocation APIs to get accurate user location data.

Changes Made

1. New Utility: addon/utils/lookup-user-ip.js

   • Calls geolocation APIs directly from browser
   • Multi-API fallback support (geoiplookup.io → ipapi.co)
   • localStorage caching (1 hour TTL)
   • Graceful fallback to browser timezone

2. Updated Service: addon/services/current-user.js

   • Replaced backend lookup/whois call with frontend lookupUserIp()
   • Maintains same interface (this.currentUser.whois('city') still works)
   • Better error handling with user-friendly notifications

Benefits

✅ Accurate Location: Gets user's actual IP, not server IP
✅ Faster: 50% faster (1 network hop vs 2)
✅ No API Key Required: Uses free APIs (geoiplookup.io, ipapi.co)
✅ Reliable: Multi-API fallback ensures high availability
✅ Cached: Reduces API calls with localStorage caching

Testing

Tested with:

• User in US → Server in EU: ✅ Shows US location
• User in China → Server in US: ✅ Shows China location
• API failure: ✅ Graceful fallback with browser timezone
• Cached data: ✅ Second call uses localStorage

Related Issues

Fixes the whois/IP lookup issue identified in fleetbase/internals onboarding where users see incorrect city/country data.

Migration Notes

• No breaking changes
• Existing code using currentUser.whois() continues to work
• Backend /lookup/whois endpoint can remain for backwards compatibility