- Add comprehensive tier feature matrix spec defining Free/Basic/Plus/Pro capabilities across recommendations, predictions, history, logs, tools, and family sharing
- Add `stripe_price_id_annual` column to plans table and rename existing column to `stripe_price_id_monthly`
- Normalize legacy fuel type aliases (petrol→e10, diesel→b7_standard) in users table
- Implement BillingController with checkout, portal, success/cancel routes supporting monthly/annual cadence
- Add admin subscription assignment in Filament user edit page with admin-granted subscription support
- Add DowngradeUserOnSubscriptionDeleted listener to disable WhatsApp/SMS preferences on subscription cancellation
- Add MissedNotificationsOverview widget to Filament user detail page
- Add PollFuelPricesTest covering auto-refresh scenarios
- Add PriceReliability enum with reliability classification based on price age
- Add fuelTypes.js constants file exporting FUEL_TYPES from window global
- Delete unused Livewire Search test and fuel type select Blade component
- Move subscription webhook listener from EventServiceProvider to AppServiceProvider
- Add FUEL_TYPES global config to app layout for client-side use
- Add Billable trait to User model and include email_verified_at in fillable
- Implement monthly/annual cadence toggle with pricing display and smart CTA routing on homepage
- Update VerifyApiKeyMiddlewareTest to use e10 instead of petrol
- Refactor PollFuelPrices to auto-refresh stale stations based on last_seen_at
- Add incremental polling with cached timestamp and effective-start-timestamp param to FuelPriceService
- Normalize amenities/fuel_types from API objects to flat arrays, skip stations missing required fields
- Log response body on API failures in ApiLogger
- Default homepage sort to 'reliable' instead of 'price'
