test: dfx_widget_service + real_unit_account_service (+9 tests)

[TaprootFreak]

Summary

Stage 15 of the coverage push. Two more DFX services.

Service	Test file	Cases
`lib/packages/service/dfx/dfx_widget_service.dart`	`test/packages/service/dfx/dfx_widget_service_test.dart`	5
`lib/packages/service/dfx/real_unit_account_service.dart`	`test/packages/service/dfx/real_unit_account_service_test.dart`	4

What each file covers

• dfx_widget_service: `wallet` getter returns `appStore.wallet.currentAccount`; `walletAddress` returns the EIP-55 hex of the primary address (pinned to the Hardhat #0 address); `isAvailable` flips with the auth-token presence on the session cache.
• real_unit_account_service: `getPortfolioHistory` GETs `/v1/realunit/account/` (path uses the wallet's primary address); parses `valueChf`/`valueEur` scaled by 100; treats null value as 0; returns `[]` on non-200 (does NOT throw — intentional).

Notes

• `real_unit_account_service` uses `appStore.wallet.currentAccount.primaryAddress.address.hexEip55` to build the request path. The test plumbs a real `SoftwareWallet` (Hardhat #0 mnemonic) through the AppStore mock so the EIP-55 hex is real, not stubbed.

Test plan

• `flutter analyze` on the two new files — clean
• `flutter test` — 9 / 9 passing locally
• CI green