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/.maestro/subflows/onboarding_returning_user.yaml

@@ -14,11 +14,13 @@
 #   - NODE_ENV != 'production' on backend (so /internal/_test routes exist).
 #
 # Path taken:
-#   Welcome carousel ("Mulai") → Home with anon banner →
-#   tap "masuk →" → /auth/register → enter +62 subscriber digits →
-#   "kirim kode" → OTP screen → peek OTP from stub → auto-submit →
-#   /auth/set-name (because AuthNeedsDisplayNameData) → enter "Maestro" →
-#   "Lanjut" → /home (returning view: "curhatan sebelumnya" header).
+#   Splash auto-advances (2026-05-26 — the 3-page welcome carousel was
+#   removed; splash self-drives to /home via context.go after ~2.5s) →
+#   Home with anon banner → tap "masuk →" → /auth/register → enter +62
+#   subscriber digits → "kirim kode" → OTP screen → peek OTP from stub →
+#   auto-submit → /auth/set-name (because AuthNeedsDisplayNameData) →
+#   enter "Maestro" → "Lanjut" → /home (returning view: "curhatan
+#   sebelumnya" header).
 #
 # Selector style: Flutter merges sibling Text widgets inside a single
 # tappable parent into ONE accessibility blob. Maestro's `text:` selector
@@ -28,15 +30,8 @@
 # inside the field's pill before typing.
 appId: ${APP_ID_ANDROID}
 ---
-# Welcome carousel — the "Mulai" button is the only Text inside its
-# tappable region, so a plain selector works.
-- extendedWaitUntil:
-    visible:
-      text: "Mulai"
-    timeout: 15000
-- tapOn:
-    text: "Mulai"
-    retryTapIfNoChange: true
+# Splash self-navigates to /home; nothing for the test to tap. Move
+# straight to the home-screen anon banner assertion.
 
 # Home — login-recover banner ("udah pernah pakai HaloBestie? … masuk →")
 # is one InkWell, so any token within its merged blob reaches the
@@ -56,12 +51,21 @@ appId: ${APP_ID_ANDROID}
     timeout: 10000
 
 # Phone input — +62 is a static prefix chip; type only subscriber digits
-# (no leading 0). +6281234567890 → 81234567890. Tap by point inside the
-# pill (well right of the +62 chip, well above the kirim-kode button).
+# (no leading 0). +6281234567890 → 81234567890.
+#
+# Selector strategy: the empty TextField has no a11y text on its own, but
+# its `hintText` ("812 3456 7890" — the placeholder phone-number group)
+# IS rendered as a Text widget inside the field's hit area, so tapping
+# the hint focuses the TextField directly. The 2026-05-26 register-screen
+# polish added a back button + logo above the field, breaking the
+# pre-existing (60%, 47%) tap-point.
+#
+# We deliberately DO NOT call `hideKeyboard` here: maestro's
+# `hideKeyboard` sends an Android BACK keypress, which pops the register
+# screen back to /home when the soft keyboard isn't actually up.
 - tapOn:
-    point: "60%, 47%"
+    text: "(?s).*812 3456 7890.*"
 - inputText: "81234567890"
-- hideKeyboard
 - tapOn:
     text: "(?s).*kirim kode.*"