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/.maestro/scripts/customer_blast_now.sh

@@ -33,4 +33,8 @@ curl -fsSL -X POST "$BACKEND_URL/api/client/chat-requests" \
   -H "Content-Type: application/json" \
   -d "{\"payment_session_id\":\"$payment_session_id\",\"topic_sensitivity\":\"regular\"}" > /dev/null
 
+# Persist payment_session_id so follow-up scripts (e.g. customer_cancel_latest_blast.sh)
+# can read it without a peek-payment endpoint. /tmp lifetime is sufficient
+# for one test run.
+echo "$payment_session_id" > /tmp/halobestie_last_blast_payment_session_id
 echo "OK — blast fired. Mitra should receive the WS event within ~1s."