Fix service worker to only unregister in development mode

[Copilot]

Service worker code was unconditionally unregistering all service workers, breaking PWA offline capabilities in production.

Changes

• Environment detection: Check if running on localhost/127.x.x.x to determine dev vs prod
• Conditional behavior: Unregister service workers only in development; register them in production
• Error handling: Added .catch() for graceful handling of registration failures

if (isLocalhost) {
    // Dev: unregister to avoid caching issues
    navigator.serviceWorker.getRegistrations().then(function(registrations) {
        for(let registration of registrations) {
            registration.unregister();
        }
    });
} else {
    // Prod: register for PWA functionality
    navigator.serviceWorker.register('service-worker.js')
        .catch(function(error) {
            console.warn('Service worker registration failed:', error);
        });
}

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