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>

client_app/.maestro/scripts/force_all_mitras_offline.sh

@@ -0,0 +1,34 @@
+#!/usr/bin/env bash
+# Force every mitra offline on the target backend. Used as a pre-step for tests
+# that verify the "no bestie available" disabled-CTA state.
+#
+# Reads BACKEND_INTERNAL_URL and a CC_JWT from the shell env (NOT from
+# .maestro/config.yaml — CC credentials should never be committed).
+#
+# Usage:
+#   CC_JWT=<token> bash client_app/.maestro/scripts/force_all_mitras_offline.sh
+
+set -euo pipefail
+
+: "${BACKEND_INTERNAL_URL:=http://192.168.88.247:3001}"
+: "${CC_JWT:?CC_JWT must be set (a valid control_center user JWT)}"
+
+# Get the list of currently online mitras from the CC dashboard endpoint.
+mitras=$(curl -fsSL "$BACKEND_INTERNAL_URL/internal/mitra-online-status" \
+  -H "Authorization: Bearer $CC_JWT" \
+  | jq -r '.data[] | select(.is_online == true) | .mitra_id')
+
+if [ -z "$mitras" ]; then
+  echo "All mitras already offline."
+  exit 0
+fi
+
+for mitra_id in $mitras; do
+  echo "Forcing $mitra_id offline..."
+  curl -fsSL -X POST "$BACKEND_INTERNAL_URL/internal/mitra-online-status/$mitra_id/offline" \
+    -H "Authorization: Bearer $CC_JWT" \
+    -H "Content-Type: application/json" \
+    -d '{}' || echo "  (failed — endpoint may not exist; check route name)"
+done
+
+echo "Done."