Mitra Bestie §1–§3: shell + Undangan + popup + chat polish

Brings the mitra app to figma-bestie parity for Home (§1), Undangan
inbox with Curhat Baru + Perpanjang tabs (§2), and the incoming-popup
+ active-chat flow (§3). Home now lives inside a StatefulShellRoute
with BestieTabBar so Profil + Undangan + Home share one shell.

- Shell: features/shell/ (StatefulShellRoute, BestieTabBar, 3 branches)
- Undangan: features/undangan/ — Curhat Baru reads
  chatRequestProvider.pendingInvites; row Terima delegates accept to
  the notifier and ChatRequestOverlay owns nav (no double-push).
  Perpanjang tab stubbed (empty state) until backend exposes
  pendingExtensionsProvider.
- Profil: features/profile/ — Bestie-styled stub
- Home: refactored to body-only (shell owns chrome)
- Popup: chat_request_overlay + chat_request_notifier updated to
  serve the list rows, not just the modal
- Chat: mitra_chat_screen polish
- Theme: accentAmber tokens for the Perpanjang tab + halo_orb widget
  (loading spinner used by undangan list states)
- Login: replace broken GoRouterState location guard with
  _expectOtpPush flag — was stacking duplicate /otp pages on OTP
  resend (see project-otp-nav-bug-fixed-2026-05-21)

Maestro:
- 17 new flows under .maestro/flows/ts-mitra-{1,2,3}-* covering home
  online/offline variants, undangan empty/populated/tolak states,
  popup curhat-baru → accept → chat → ended banner, plus popup
  dismiss/expire/cancelled edge cases
- 4 new §A OTP flows (07/08/09/10) for invalid/mismatch/expired/cooldown
- Helper scripts: force_mitra_online/offline, force_pairing_timeout,
  force_session_expires_at, delete_mitra_status_row,
  customer_blast_now (js), customer_cancel_latest_blast
- Backend: POST /internal/_test/delete-mitra-status-row supports the
  "fresh mitra with no status row" test setup

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

mitra_app/lib/features/auth/screens/login_screen.dart

@@ -33,6 +33,14 @@ class _LoginScreenState extends ConsumerState<LoginScreen> {
   int _lockoutSeconds = 0;
   Timer? _lockoutTimer;
 
+  // Set true in _submit() right before requestOtp; cleared after the listener
+  // pushes /otp. Without this flag the listener fires on every subsequent
+  // auth-state transition (verifyOtp's AsyncLoading / AsyncError preserve the
+  // OtpSentData via Riverpod's copyWithPrevious) and stacks duplicate /otp
+  // pages on top of itself, because GoRouterState.of(context) returns the
+  // LoginScreen's own page state (/login), not the navigator's top route.
+  bool _expectOtpPush = false;
+
   @override
   void initState() {
     super.initState();
@@ -46,18 +54,17 @@ class _LoginScreenState extends ConsumerState<LoginScreen> {
         (prev, next) async {
       if (!mounted) return;
       final data = next.valueOrNull;
-      // Push to /otp only when the *current top route* is /login. This
-      // protects against the OtpScreen's resend stacking a second /otp on
-      // top of itself (login_screen's listener stays alive on the nav stack
-      // and would otherwise fire on every fresh MitraAuthOtpSentData).
-      if (data is MitraAuthOtpSentData) {
-        final location = GoRouterState.of(context).matchedLocation;
-        if (location == '/login') {
-          context.push('/otp', extra: _e164Phone());
-        }
+      if (data is MitraAuthOtpSentData && _expectOtpPush) {
+        _expectOtpPush = false;
+        context.push('/otp', extra: _e164Phone());
         return;
       }
       if (next is! AsyncError) return;
+      // Only handle errors for our own requestOtp call. verifyOtp errors
+      // belong to OtpScreen — without this gate LoginScreen's default
+      // snackbar would paint on top of OtpScreen's inline error.
+      if (!_expectOtpPush) return;
+      _expectOtpPush = false;
 
       final err = next.error;
       if (err is! MitraAuthError) {
@@ -154,6 +161,7 @@ class _LoginScreenState extends ConsumerState<LoginScreen> {
   Future<void> _submit() {
     final phone = _e164Phone();
     setState(() => _phoneErrorText = null);
+    _expectOtpPush = true;
     return ref.read(mitraAuthProvider.notifier).requestOtp(phone);
   }