Phase 3.3: topic sensitivity + Phase 3.4: auth foundation

Phase 3.3 — Session Topic Sensitivity (complete):
- Backend: topic_sensitivity column + session_sensitivity_log, sensitivity service
  (flip with one-way-latch + audit), PATCH /api/shared/chat/sessions/:id/topic,
  topic carried in pairing + extension WS payloads, CC filter + sensitive stats
  + per-mitra sensitive columns on activity page
- client_app: TopicSelectionBottomSheet before pricing, topic flows through
  pairing request, silent WS handler for session_topic_updated
- mitra_app: SensitivityBadge + SensitivityTheme + sensitivityConfigProvider,
  overlay badge + yellow accent, chat screen app-bar toggle with configurable
  confirmation + latch, extension card shows current flag, history + transcript
  yellow theme
- control_center: Sensitivitas Topik settings section, topic filter + column
  with inline audit log, sensitive stats dashboard card, mitra activity
  sensitive columns with QC flag

Phase 3.4 — Self-Managed Auth (foundation only):
- Migration: auth_sessions + otp_requests tables, social identity columns on
  customers, password_hash + lockout on control_center_users, OTP + CC lockout
  app_config keys
- New services: password (bcrypt + complexity), token (JWT HS256 + refresh
  rotation, session_id claim pre-wires future Valkey revocation),
  social-identity (Google + Apple JWKS), OTP (Fazpass stub — real API TBD)
- Constants: AuthProvider + OtpChannel
- Middleware, auth route rewrites, WS auth update, Firebase → FCM isolation
  still pending (next chunk); Fazpass docs + Apple Developer setup still
  required before E2E testing

Docs:
- requirement/phase3.3.md, phase3.3-plan.md, phase3.3-testing.md
- requirement/phase3.4.md, phase3.4-plan.md

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

client_app/lib/core/pairing/pairing_notifier.dart

@@ -60,12 +60,17 @@ class Pairing extends _$Pairing {
   @override
   PairingData build() => const PairingInitialData();
 
-  Future<void> requestPairing() async {
-    await _doPairingRequest({});
+  Future<void> requestPairing({required TopicSensitivity topicSensitivity}) async {
+    await _doPairingRequest({'topic_sensitivity': topicSensitivity.value});
   }
 
-  Future<void> requestPairingWithTier({int? durationMinutes, int? price, bool isFreeTrial = false}) async {
-    final body = <String, dynamic>{};
+  Future<void> requestPairingWithTier({
+    int? durationMinutes,
+    int? price,
+    bool isFreeTrial = false,
+    required TopicSensitivity topicSensitivity,
+  }) async {
+    final body = <String, dynamic>{'topic_sensitivity': topicSensitivity.value};
     if (isFreeTrial) {
       body['is_free_trial'] = true;
     } else {