Fix orphan references after shitcoin nuke (build round 2)

Stragglers that weren't in any agent's batch but referenced the removed
identifiers:

- tool/configure.dart: stripped 'backupSeeds(Box<HavenSeedStore>)'
  abstract method from generateWownero's emitted template + the
  haven_seed_store.dart import. CI regenerates lib/wownero/wownero.dart
  from this template each build, so the previous lib/wownero/wownero.dart
  cleanup got reverted on rebuild. This is the actual fix.
- lib/core/trade_monitor.dart + lib/view_model/trade_details_view_model.dart:
  removed JupiterExchangeProvider import + ExchangeProviderDescription.jupiter
  switch cases (provider + URL builder).
- lib/src/screens/dashboard/dashboard_page.dart: deleted _showHavenPopup
  helper + its call site + the haven_wallet_removal_popup import.
- lib/src/widgets/haven_wallet_removal_popup.dart: deleted (no callers).
- lib/src/screens/dashboard/pages/balance/crypto_balance_widget.dart:
  removed the zcash 'missing funds' InfoCard and the decred 'syncing'
  InfoCard widgets, plus their _dismissZcash and _rescanInternalChangeZcash
  handlers.
- lib/src/screens/settings/connection_sync_page.dart: removed the TronGrid
  history toggle row.
- lib/src/widgets/bottom_sheet/payment_confirmation_bottom_sheet.dart:
  _isTokenSelectionFlow now only checks evmNetworkSelection (was also
  branching on solana/tronTokenSelection enum values that no longer exist).

Generated .g.dart files for dashboard_view_model and connection_sync_view_model
still reference removed methods (rescanInternalChangeZcash, dismissZcash,
canUseTronGrid, setUseTronGrid). Those will be regenerated by build_runner
on next CI run and the methods will fall out — no manual fix needed.

tool/configure.dart

@@ -517,7 +517,6 @@ import 'package:hash_wallet/view_model/send/output.dart';
 import 'package:cw_core/crypto_currency.dart';
 import 'package:hash_wallet/core/key_service.dart';
 import 'package:hash_wallet/core/secure_storage.dart';
-import 'package:hash_wallet/entities/haven_seed_store.dart';
 import 'package:cw_core/cake_hive.dart';
 import 'package:cw_core/wallet_info.dart';
 import 'package:cw_core/wallet_type.dart';
@@ -654,7 +653,6 @@ abstract class Wownero {
   Map<String, String> pendingTransactionInfo(Object transaction);
   String getLegacySeed(Object wallet, String langName);
   Map<String, List<int>> debugCallLength();
-  Future<void> backupSeeds(Box<HavenSeedStore> havenSeedStore);
 }
 
 abstract class WowneroSubaddressList {