[Bugfix] Back Navigation in Seed Entry Views

[PROWLERx15]

Description

Problem or Issue being addressed

Pressing BACK on the first word of seed entry takes you straight to the Main Menu instead of going back to the Seeds Menu where you came from.

Current behavior:
Seeds Menu → Enter 12-word seed → Back → Main Menu
Seeds Menu → Enter 24-word seed → Back → Main Menu

Expected behavior:
Seeds Menu → Enter 12-word seed → Back → Seeds Menu
Seeds Menu → Enter 24-word seed → Back → Seeds Menu

Solution

SeedMnemonicEntryView: When pressing BACK on the first word, the old code hard-coded a jump to MainMenuView. Changed it to use BackStackView instead, so it naturally returns to wherever the user came from, either LoadSeedView (the normal "enter a seed" path) or SeedSelectSeedView (when entering a seed mid-flow, like during sign message).
The pending mnemonic is still properly discarded.

Additional Information

Screenshots

No UI changes, only navigation logic.

This pull request is categorized as a:

• New feature
• Bug fix
• Code refactor
• Documentation
• Other

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Checklist

I ran pytest locally

• All tests passed before submitting the PR
• I couldn't run the tests
• N/A

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I included screenshots of any new or modified screens

Should be part of the PR description above.

• Yes
• No
• N/A

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I added or updated tests

Any new or altered functionality should be covered in a unit test. Any new or updated sequences require FlowTests.

• Yes
• No, I’m a fool
• N/A

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I tested this PR hands-on on the following platform(s):

• Raspberry Pi OS Manual Build
• SeedSigner OS on a Pi0/Pi0W board
• Emulator

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• Keep your changes limited in scope.
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• I understand

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[Chaitanya-Keyal]

Thanks for the PR, this is a great catch!

However, I was unable to reproduce the issue you mention with SeedFinalizeView; the back button is explicitly disabled for SeedFinalizeScreen, so RET_CODE__BACK_BUTTON should not be reachable there in normal flow:

seedsigner/src/seedsigner/gui/screens/seed_screens.py

Line 423 in 2c486eb

self.show_back_button = False

Given that, I think we should rather just remove the back button elif branch in SeedFinalizeView (and any test that relies on that unreachable path), and keep the mnemonic-entry fix/tests which address the real issue.

If you can share a concrete repro path or traceback for the finalize crash, happy to take another look.

[PROWLERx15]

Thanks for the PR, this is a great catch!

However, I was unable to reproduce the issue you mention with SeedFinalizeView; the back button is explicitly disabled for SeedFinalizeScreen, so RET_CODE__BACK_BUTTON should not be reachable there in normal flow:

seedsigner/src/seedsigner/gui/screens/seed_screens.py

Line 423 in 2c486eb

self.show_back_button = False

Given that, I think we should rather just remove the back button elif branch in SeedFinalizeView (and any test that relies on that unreachable path), and keep the mnemonic-entry fix/tests which address the real issue.

If you can share a concrete repro path or traceback for the finalize crash, happy to take another look.

You're right, the back button is disabled on SeedFinalizeScreen so that branch was dead code. I've removed it along with the test. Thanks for catching that :)

[Chaitanya-Keyal]

Tested ACK at ef7d371