Remove prediction API endpoint and integrate into stations search

Consolidate prediction functionality by merging /api/prediction endpoint into /api/stations response. Move prediction logic from PredictionController into StationController, returning prediction data alongside station results. Replace usePrediction composable with unified useStations that returns {stations, meta, prediction}. Remove PredictionRequest, related tests, and unused Vue components (FuelFinderTest, MapTest, RecommendationTest, StationListTest). Add PredictionFull component and UpsellBanner. Extend NationalFuelPredictionService to include weekly_summary (7-day series, yesterday/today averages, cheapest/priciest days) and oil signal from price_predictions table. Update Home.vue to consume prediction from stations response. Add Plan::resolveCadenceForUser helper and configure Cashier to use custom Subscription model.

resources/js/composables/useAuth.js

@@ -19,6 +19,22 @@ export function useAuth() {
         return ['basic', 'plus', 'pro'].includes(userTier.value)
     })
 
+    const subscriptionCancelled = computed(() => {
+        return user.value?.subscription_cancelled ?? false
+    })
+
+    const subscriptionCadence = computed(() => {
+        return user.value?.subscription_cadence ?? null
+    })
+
+    const subscribedAt = computed(() => {
+        return user.value?.subscribed_at ?? null
+    })
+
+    const subscriptionExpiresAt = computed(() => {
+        return user.value?.subscription_expires_at ?? null
+    })
+
     async function fetchUser() {
         if (fetched.value) {
             return
@@ -68,6 +84,10 @@ export function useAuth() {
         isAuthenticated,
         userTier,
         isPaidTier,
+        subscriptionCancelled,
+        subscriptionCadence,
+        subscribedAt,
+        subscriptionExpiresAt,
         fetchUser,
         clearUser,
         logout,