Phase 3 testing fixes: Fastify 5, SSE→WebSocket+FCM, enums, security, session lifecycle

- Upgrade Fastify 4→5 with all plugins (@fastify/websocket 11, cors 11, sensible 6)
- Migrate all SSE endpoints to WebSocket + FCM push (mitra chat requests, customer pairing status)
- Add flutter_local_notifications for foreground push notifications with sound
- Add splash screen to both apps (hide auth loading flash)
- Introduce constants/enums across entire codebase (no raw string literals)
- Move price tiers from hardcoded array to app_config DB (data-driven, includes 1-min test tier)
- Add session ownership validation on all shared chat routes
- Add ownership checks on endSession, respondToExtension, requestExtension
- Fix session timer: auto-complete expired/stale sessions on server restart
- Add 5-min grace period for abandoned closing sessions
- Fix extension flow: proper session_resumed handling, clearExtensionRequest, closure grace timer cleanup
- Fix chat screens: ConnectChat in initState, session status check on connect
- Fix customer expired view: 5-min countdown, closure state priority over expired state
- Fix mitra extension UI: loading spinner, disable buttons, handle EXTENSION_RESOLVED error
- Fix GoRouter navigation consistency (no more Navigator.pushNamed)
- Fix goodbye view keyboard overflow (SingleChildScrollView)
- Add active session card on customer home screen with refresh on navigate back
- Fix PricingBottomSheet extension mode (RequestExtension instead of new pairing)
- Send session_resumed to both parties on extension accept

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

backend/src/services/pricing.service.js

@@ -2,8 +2,9 @@ import { getDb } from '../db/client.js'
 
 const sql = getDb()
 
-// Mock price tiers (will come from Control Center config later)
-const PRICE_TIERS = [
+// Default tiers as fallback
+const DEFAULT_TIERS = [
+  { duration_minutes: 1, price: 5000, label: '1 Menit (Test)' },
   { duration_minutes: 15, price: 30000, label: '15 Menit' },
   { duration_minutes: 30, price: 60000, label: '30 Menit' },
   { duration_minutes: 45, price: 100000, label: '45 Menit' },
@@ -11,10 +12,14 @@ const PRICE_TIERS = [
   { duration_minutes: 1440, price: 250000, label: '24 Jam' },
 ]
 
-export const getPriceTiers = () => PRICE_TIERS
+export const getPriceTiers = async () => {
+  const [row] = await sql`SELECT value FROM app_config WHERE key = 'price_tiers'`
+  return row?.value?.tiers ?? DEFAULT_TIERS
+}
 
-export const isValidTier = (durationMinutes, price) => {
-  return PRICE_TIERS.some(
+export const isValidTier = async (durationMinutes, price) => {
+  const tiers = await getPriceTiers()
+  return tiers.some(
     (t) => t.duration_minutes === durationMinutes && t.price === price
   )
 }
@@ -41,7 +46,7 @@ export const isCustomerEligibleForFreeTrial = async (customerId) => {
 }
 
 export const getPricingForCustomer = async (customerId) => {
-  const tiers = getPriceTiers()
+  const tiers = await getPriceTiers()
   const freeTrialEligible = await isCustomerEligibleForFreeTrial(customerId)
   const freeTrial = await getFreeTrial()