test: wallet/pdf services + home_bloc onboarding flow (+17 tests)

[TaprootFreak]

Summary

Stage 11 of the coverage push.

File under test	Test file	Cases
`lib/packages/service/dfx/real_unit_wallet_service.dart`	`test/packages/service/dfx/real_unit_wallet_service_test.dart`	3
`lib/packages/service/dfx/real_unit_pdf_service.dart`	`test/packages/service/dfx/real_unit_pdf_service_test.dart`	9
`lib/screens/home/bloc/home_bloc.dart`	`test/screens/home/home_bloc_test.dart`	5

What each file covers

• real_unit_wallet_service: `getWalletStatus` GET shape with the Bearer JWT, parses both `isRegistered` branches when `userData` is null, throws ApiException on non-200.
• real_unit_pdf_service: `getBalanceReport` POSTs the BalancePdfDto payload (`address`, currency code, uppercased language code); accepts 201; ApiException on non-2xx. `getTransactionsReceipt` (multi) posts `txHashes` + currency, defaults to CHF, ApiException on non-2xx. `getTransactionReceipt` (single) posts `txHash` + currency, defaults to CHF, ApiException on non-2xx.
• home_bloc: initial `CheckWalletExistsEvent` for three branches: no wallet → `onboardingCompleted` forced false; wallet+terms accepted → `onboardingCompleted=true`; wallet without terms → `onboardingCompleted=false`. `CompleteOnboardingEvent` writes `termsAccepted=true` and emits. `AcceptSoftwareTermsEvent` writes `softwareTermsAccepted=true` and emits.

Notes

• The PDF DTOs serialize `txId` as `txHash` on the wire (single) and `txIds` as `txHashes` (multi). The tests pin these names explicitly to lock the wire contract.
• `Language` codes are uppercased in the balance-pdf payload (`Language.de` → `'DE'`). Also pinned.

Excluded (and why)

• Other `home_bloc` handlers (`LoadCurrentWallet`, `DeleteCurrentWallet`, `LoadWallet`, `SyncWalletServices`, `DebugAuthComplete`) all touch `BalanceService.startSync` / `TransactionHistoryService.apiBasedSync` / `DfxWidgetService.getAuthToken` plus `AppStore.wallet` mutation. Each is meaningful but needs more dependency plumbing — deserves its own focused PR.
• `settings_user_data_cubit` — still deferred (coordinates 3 services + Country lookups + multi-branch KYC step status); will land separately.

Test plan

• `flutter analyze` on all three new files — clean
• `flutter test` — 17 / 17 passing locally
• CI green