refactor: migrate fully to Supabase, remove Firebase/Render/Python backend

- DELETED: entire backend/ (Python/FastAPI — replaced by Supabase)
- DELETED: old/ directory (obsolete code)
- DELETED: render.yaml, inject_api.py, check_tags.py, PENDING_FOR_TOMORROW.md
- DELETED: frontend/src/firebaseConfig.ts (Firebase Auth replaced by Supabase Auth)
- DELETED: frontend/src/services/apiClient.ts (HTTP client for dead backend)

- MIGRATED services to Supabase native:
  schedulesService, favoritesService, usersService,
  telemetryService (stub), reportsService, analyticsService (stub)

- MIGRATED stores/favorites.ts to Supabase direct queries
- MIGRATED views: SplashScreen, AdminTaxis, AdminDrivers, StrategicAnalytics
- MIGRATED utils/imageUrl.ts to Supabase Storage URLs

- FIXED router/index.ts: guard now uses supabase.auth.getSession()
  instead of old localStorage auth_token (fixes logout + map loading)
- FIXED AuthView.vue: removed aggressive watch({ immediate: true })
  that caused wrong redirects on map route
- FIXED SplashScreen.vue: navigate() now reads Supabase session + role
- FIXED RLS: added INSERT policy on public.users for trigger
- CONFIRMED: admin@sibu.com assigned ADMIN role in Supabase

frontend/src/views/CouponsView.vue

@@ -1,8 +1,8 @@
-<script setup lang="ts">
+<script setup lang="ts">
 import { onMounted, ref, computed } from 'vue'
 import { useI18n } from 'vue-i18n'
 import { useCouponStore } from '@/stores/coupon'
-import { API_URL } from '@/services/apiClient'
+import { SUPABASE_URL } from '@/supabase'
 import type { Coupon } from '@/types'
 import FavoriteButton from '@/components/FavoriteButton.vue'
 
@@ -644,3 +644,4 @@ function getCategoryIcon(category?: string | null) {
 @keyframes spin { 100% { transform: rotate(360deg); } }
 </style>
 
+