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/useStations.js

@@ -4,6 +4,7 @@ import api from '../axios.js'
 export function useStations() {
     const stations = ref([])
     const meta = ref(null)
+    const prediction = ref(null)
     const loading = ref(false)
     const error = ref(null)
 
@@ -12,6 +13,7 @@ export function useStations() {
         error.value = null
         stations.value = []
         meta.value = null
+        prediction.value = null
 
         const params = { fuel_type: fuelType, radius, sort }
 
@@ -26,6 +28,7 @@ export function useStations() {
             const response = await api.get('/stations', { params })
             stations.value = response.data.data
             meta.value = response.data.meta
+            prediction.value = response.data.prediction ?? null
         } catch (err) {
             error.value = err.response?.data?.errors
                 ?? { general: ['Unable to load stations. Please try again.'] }
@@ -37,9 +40,10 @@ export function useStations() {
     function reset() {
         stations.value = []
         meta.value = null
+        prediction.value = null
         error.value = null
         loading.value = false
     }
 
-    return { stations, meta, loading, error, search, reset }
+    return { stations, meta, prediction, loading, error, search, reset }
 }