fix: show passphrase toast on sheet

[piotr-iohk]

Fixes #1161

This PR shows the wrong-passphrase error toast on top of the hardware transfer passphrase sheet.

Description

Entering the wrong passphrase on Transfer to Spending already refused the sign and sent the error toast, but the toast sat behind the modal sheet. It was only visible after Cancel. The toast now renders inside the sheet, with the same frosted style as elsewhere.

Preview

Screen_Recording_20260819_103340_Bitkit.Regtest.mp4

QA Notes

Manual Tests

• 1. Force-quit after pairing a hidden hardware wallet → Transfer → Spending → Open Trezor Connect → enter a wrong passphrase → Continue: error toast is visible on the passphrase sheet (not only after Cancel).
• 2. Same sheet → Cancel: toast is gone or already dismissed; no extra wallet tile; nothing signed.
• 3. regression: same flow with the correct passphrase → Continue: sheet closes and signing proceeds as before.

Automated Checks

• Existing mismatch coverage in TransferViewModelTest.kt is unchanged (toast is still sent; this PR only changes where it is drawn).
• Local compileDevDebugKotlin passed.
• CI: standard compile, unit test, and detekt checks run by the PR bot.

[greptile-apps]

Greptile Summary

The PR renders the existing app-wide toast inside the hardware-wallet passphrase modal so wrong-passphrase errors remain visible above the sheet.

• Adds a sheet-local toast host connected to AppViewModel.currentToast.
• Applies the existing frosted haze treatment behind the toast.
• Adds a changelog entry for the visibility fix.

Confidence Score: 5/5

The PR appears safe to merge with no actionable regressions identified.

The sheet-local host observes the existing toast state and forwards the established dismissal and gesture callbacks while placing the toast above the modal that previously obscured it.

Important Files Changed

Filename	Overview
app/src/main/java/to/bitkit/ui/screens/transfer/hardware/HwPassphrasePromptSheet.kt	Adds an in-sheet host for the shared toast state, preserving existing dismissal, pause, resume, and haze behavior without an established defect.
changelog.d/next/1161.fixed.md	Accurately documents that wrong-passphrase errors are now visible over the hardware transfer passphrase sheet.

_{Reviews (1): Last reviewed commit: "fix: harden passphrase sheet toast host" | Re-trigger Greptile}