Phase 5/6 polish: end-session flow, notif sound on API 33+, Xendit webview

Customer end-of-session (figma §6):
- PricingBottomSheet: ghost "cukup, akhiri sesi" CTA + dedup divider
- chat_screen._runEndSessionFlow chains ConfirmEndStep1 → ConfirmEndStep2
  → ClosingMessageSheet (or "lewati saja" → close + /home). The four
  popup/sheet widgets already existed; this commit just wires them
- showModalBottomSheet: showDragHandle=false to suppress the Material 3
  auto-injected handle that was stacking with our own pill

Notification sound on API 33+:
- Bump channel halobestie_chat_v1 → halobestie_chat_v2, created from
  native Kotlin in MainActivity.kt with AudioAttributes contentType
  CONTENT_TYPE_SONIFICATION. flutter_local_notifications' default of
  CONTENT_TYPE_UNKNOWN was causing Android 13 to silently drop audio
  focus while the notification still posted (isNoisy=true). Both apps
- Backend FCM payload channelId updated to v2
- AndroidManifest meta-data: default_notification_icon + color → brand
  silhouette tinted pink instead of generic Android bell. Both apps

Customer pairing reliability:
- pairing_notifier: applyPairedFromPush({sessionId, mitraName}) unsticks
  searching screen when WS push failed and FCM/active-session-poll is
  the first signal. Idempotent across PairingSearchingData,
  PairingTargetedWaitingData, PairingErrorData (covers ALREADY_ACTIVE)
- notification_service: dispatches every FCM data payload to an
  onDataMessage callback (foreground + tap + cold-start). main.dart
  wires that to applyPairedFromPush on type=='paired'. Foreground
  'paired' no longer renders a local banner — screen self-advances
- main.dart activeSession listener also calls applyPairedFromPush when
  a session appears server-side while pairing is in a waiting state.
  Covers stale ALREADY_ACTIVE recovery without a full page refresh

Auth refresh token race:
- auth_notifier._refreshFromStorage shares a single in-flight Future
  across all callers (Auth.build + 401-retry path). Backend rotates
  refresh tokens, so concurrent callers using the same stored token
  would race → loser 401s → catch wipes flutter_secure_storage → user
  appears logged out after kill+reopen

Polish:
- method_pick_screen: resizeToAvoidBottomInset=false — prevents the
  one-frame overflow when entering with the previous screen's keyboard
  still animating out
- bestie_history: BestieHistoryItem now carries `status` (backend
  already returns it). Removed _rawHistoryProvider that fetched the
  same endpoint just to read status; the two providers could go out
  of sync mid-rebuild and throw RangeError(length) on indexing

Xendit Stage 8 (carried from WIP):
- xendit_checkout_screen: embedded webview hosting Xendit's invoice
  page (intercepts halobestie:// deeplink + return-page URLs for
  deterministic pop)
- waiting_payment_screen: auto-pushes the webview when the backend
  payload includes xendit_invoice_url; spinner card + "Buka ulang
  halaman pembayaran" CTA for the QR-fallback path
- pubspec: webview_flutter ^4.13.0

Maestro infra:
- subflows/onboarding_returning_user: drop the "Mulai" carousel wait
  (splash auto-advances since 2026-05-26); tap phone-field hint
  instead of point; drop hideKeyboard (sends BACK → /home when the
  IME isn't actually up)
- New flow ts-customer-06-01-end_session_via_timeup_sheet: drives
  the full path to the chat-expired banner. Last step blocked by a
  Maestro+Flutter gesture quirk on the perpanjang ElevatedButton
  (raw `adb input tap` works at the same coords). Documented in
  memory; deeplink fixture or manual verify recommended
- ChatExpiredBanner button wrapped with Semantics(identifier:
  'chat_extend_button', button: true, onTap: …) — good hygiene for
  future tests even though it doesn't fix the dadb tap issue

.dev/: tracked wsl_emulator_bridge.ps1 + wsl_tcp_relay.py for
Maestro-on-WSL setup (Windows-side netsh portproxy + WSL-side
loopback relays). Both referenced from existing CLAUDE.md notes.

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

client_app/lib/features/chat/widgets/chat_expired_banner.dart

@@ -57,22 +57,35 @@ class ChatExpiredBanner extends StatelessWidget {
             ),
           ),
           const SizedBox(width: 8),
-          ElevatedButton(
-            onPressed: onExtend,
-            style: ElevatedButton.styleFrom(
-              backgroundColor: Colors.white,
-              foregroundColor: HaloTokens.brand,
-              shape: RoundedRectangleBorder(borderRadius: BorderRadius.circular(999)),
-              padding: const EdgeInsets.symmetric(horizontal: 12, vertical: 6),
-              minimumSize: const Size(0, 32),
-              elevation: 0,
-              textStyle: const TextStyle(
-                fontFamily: HaloTokens.fontBody,
-                fontSize: 11.5,
-                fontWeight: FontWeight.w700,
+          // Semantics wrapper exposes the button via Android's resource-id so
+          // maestro can find it via `id:` selector AND triggers onExtend
+          // directly on a11y CLICK action (instead of synthesized coord-tap
+          // which doesn't reliably fire this ElevatedButton's onPressed —
+          // confirmed: raw `adb input tap` works, maestro's tap does not).
+          // `onTap: onExtend` makes the Semantics node itself clickable so
+          // Android's UiAutomator routes node.performAction(ACTION_CLICK)
+          // → onExtend without needing the child button's gesture detector.
+          Semantics(
+            identifier: 'chat_extend_button',
+            button: true,
+            onTap: onExtend,
+            child: ElevatedButton(
+              onPressed: onExtend,
+              style: ElevatedButton.styleFrom(
+                backgroundColor: Colors.white,
+                foregroundColor: HaloTokens.brand,
+                shape: RoundedRectangleBorder(borderRadius: BorderRadius.circular(999)),
+                padding: const EdgeInsets.symmetric(horizontal: 12, vertical: 6),
+                minimumSize: const Size(0, 32),
+                elevation: 0,
+                textStyle: const TextStyle(
+                  fontFamily: HaloTokens.fontBody,
+                  fontSize: 11.5,
+                  fontWeight: FontWeight.w700,
+                ),
               ),
+              child: const Text('perpanjang'),
             ),
-            child: const Text('perpanjang'),
           ),
         ],
       ),