Phase 3.7: paid pairing flow + returning chat + extension flip

- Backend: payment_sessions + pairing_failures tables; payment.service.js
  and pairing-failure.service.js (new); rewritten pairing.service.js
  (payment-gated blast + targeted "Curhat lagi" + cancel + fallback);
  rewritten extension.service.js (data-driven auto-approve with offline
  safeguard, charge-at-approval); pricing.service.js (extension tiers
  without free trial); mitra-status.service.js (countAvailableMitras
  cached path); 60s sweeper for stale payment sessions
- Backend routes: client.payment.routes, client.mitra-availability.routes,
  internal/failed-pairings.routes; client.chat.routes rewritten for
  payment-gated start + /returning + /cancel + /fallback-to-blast;
  internal/config.routes adds 4 new keys with Valkey invalidate publish
- client_app: mitra-availability poll, payment screen + notifier, pairing
  notifier rewrite (PairingTargetedWaiting + PairingFailed states),
  targeted-waiting overlay + bestie-unavailable dialog, "Curhat lagi"
  CTA, failed-pairing terminal, extension via payment-session
- mitra_app: PairingRequestType enum, returning-chat 20s countdown
  auto-dismiss, extension card "otomatis disetujui" copy
- control_center: 4 new config rows in Settings, Failed Pairings page
  (filter + paginate + action menu), sidebar + route registered
- Test infrastructure: Vitest backend (7/7 pass), Playwright CC (4/4
  pass), Maestro mobile scaffold (CLI install pending)
- Bugs found via Playwright + fixed: LoginPage labels not associated
  with inputs (a11y); backend internal CORS missing PATCH/PUT/DELETE
  in allow-methods (silent settings breakage in browsers since Stage 4)
- Docs: phase3.7.md PRD, phase3.7-plan.md, phase3.7-questions.md (Q&A),
  phase3.7-testing.md (E2E checklist), phase3.7-test-run-2026-05-03.md
  (today's run results)

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

backend/src/services/config.service.js

@@ -1,4 +1,5 @@
 import { getDb } from '../db/client.js'
+import { ExtensionTimeoutAction } from '../constants.js'
 
 const sql = getDb()
 
@@ -27,6 +28,10 @@ export const setMaxCustomersPerMitra = async (value) => {
     VALUES ('max_customers_per_mitra', ${sql.json({ value })}, NOW())
     ON CONFLICT (key) DO UPDATE SET value = EXCLUDED.value, updated_at = NOW()
   `
+  // Capacity changed → drop cached availability snapshot.
+  // Imported lazily to avoid a circular import (mitra-status.service uses config).
+  const { invalidateAvailabilityCache } = await import('./mitra-status.service.js')
+  invalidateAvailabilityCache()
   return { max_customers_per_mitra: value }
 }
 
@@ -61,7 +66,8 @@ export const setFreeTrialConfig = async ({ enabled, duration_minutes }) => {
 
 export const getExtensionTimeoutConfig = async () => {
   const [row] = await sql`SELECT value FROM app_config WHERE key = 'extension_timeout_seconds'`
-  return { extension_timeout_seconds: row?.value?.value ?? 60 }
+  // Default 10s pairs with the auto-approve-on-timeout flow; raise this if you change the policy to auto-reject.
+  return { extension_timeout_seconds: row?.value?.value ?? 10 }
 }
 
 export const setExtensionTimeoutConfig = async (seconds) => {
@@ -222,3 +228,61 @@ export const setCcLoginLockoutConfig = async ({ max_attempts, lockout_minutes })
   }
   return getCcLoginLockoutConfig()
 }
+
+// --- Paid Pairing Flow + Returning-Chat + Extension Flip ---
+
+export const getPaymentSessionTimeoutMinutes = async () => {
+  const [row] = await sql`SELECT value FROM app_config WHERE key = 'payment_session_timeout_minutes'`
+  return { payment_session_timeout_minutes: row?.value?.value ?? 20 }
+}
+
+export const setPaymentSessionTimeoutMinutes = async (value) => {
+  await sql`
+    INSERT INTO app_config (key, value, updated_at)
+    VALUES ('payment_session_timeout_minutes', ${sql.json({ value })}, NOW())
+    ON CONFLICT (key) DO UPDATE SET value = EXCLUDED.value, updated_at = NOW()
+  `
+  return { payment_session_timeout_minutes: value }
+}
+
+export const getReturningChatConfirmationTimeoutSeconds = async () => {
+  const [row] = await sql`SELECT value FROM app_config WHERE key = 'returning_chat_confirmation_timeout_seconds'`
+  return { returning_chat_confirmation_timeout_seconds: row?.value?.value ?? 20 }
+}
+
+export const setReturningChatConfirmationTimeoutSeconds = async (value) => {
+  await sql`
+    INSERT INTO app_config (key, value, updated_at)
+    VALUES ('returning_chat_confirmation_timeout_seconds', ${sql.json({ value })}, NOW())
+    ON CONFLICT (key) DO UPDATE SET value = EXCLUDED.value, updated_at = NOW()
+  `
+  return { returning_chat_confirmation_timeout_seconds: value }
+}
+
+export const getExtensionDefaultActionOnTimeout = async () => {
+  const [row] = await sql`SELECT value FROM app_config WHERE key = 'extension_default_action_on_timeout'`
+  return { extension_default_action_on_timeout: row?.value?.value ?? ExtensionTimeoutAction.AUTO_APPROVE }
+}
+
+export const setExtensionDefaultActionOnTimeout = async (value) => {
+  await sql`
+    INSERT INTO app_config (key, value, updated_at)
+    VALUES ('extension_default_action_on_timeout', ${sql.json({ value })}, NOW())
+    ON CONFLICT (key) DO UPDATE SET value = EXCLUDED.value, updated_at = NOW()
+  `
+  return { extension_default_action_on_timeout: value }
+}
+
+export const getPairingBlastTimeoutSeconds = async () => {
+  const [row] = await sql`SELECT value FROM app_config WHERE key = 'pairing_blast_timeout_seconds'`
+  return { pairing_blast_timeout_seconds: row?.value?.value ?? 60 }
+}
+
+export const setPairingBlastTimeoutSeconds = async (value) => {
+  await sql`
+    INSERT INTO app_config (key, value, updated_at)
+    VALUES ('pairing_blast_timeout_seconds', ${sql.json({ value })}, NOW())
+    ON CONFLICT (key) DO UPDATE SET value = EXCLUDED.value, updated_at = NOW()
+  `
+  return { pairing_blast_timeout_seconds: value }
+}