[CI] Fix for build.yml and writing version.json

[newtonick]

Description

Problem or Issue being addressed

Build images (.img files) produced by the SeedSigner CI build action hang at the logo after being flashed, even though the build passes.

#858 added a Version screen that reads src/seedsigner/version.json during startup. If the file is missing or incomplete, the resulting exception terminates the app.

The delete unnecessary files step reduces the checkout to src/ before the build container starts:

cd seedsigner-os/opt/rootfs-overlay/opt
find . -mindepth 1 -maxdepth 1 ! -name src -exec rm -rf {} +

This removes .git/ and tools/, which tools/write_versionfile.py needs to generate version.json. The build log confirms that only src/ remains when the container runs.

Solution

Remove the delete unnecessary files workflow step. The updated seedsigner-os build.sh writes the version file first, then calls delete_unnecessary_files() before Buildroot packages the image.

I checked its removal list against every top-level entry in this repository. .git/, tools/, and the other unnecessary files are removed before make, so they do not reach the image.

After the build, validate the generated file with jq:

jq -e '.name and .fork and .short_commit_hash and .timestamp' src/seedsigner/version.json

A failed version write still stops the build immediately. This additional check catches an incomplete file that might otherwise ship in an unbootable image.

Additional Information

This requires the matching seedsigner-os PR SeedSigner/seedsigner-os#115 to be merged first. It runs the version-writing step during --skip-repo builds and sets Git's safe.directory so the container can read the version data.

Screenshots

N/A. This PR only changes the CI build workflow.

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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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I have reviewed these notes:

• Keep your changes limited in scope.
• If you uncover other issues or improvements along the way, ideally submit those as a separate PR.
• The more complicated the PR, the harder it is to review, test, and merge.
• We appreciate your efforts, but we're a small team of volunteers so PR review can be a very slow process.
• Please only "@" mention a contributor if their input is truly needed to enable further progress.

• I understand

[newtonick]

Because current CI is broken; I am going to fast track this PR to be merged. In general I always want the dev/main branches of both of these repos in working states. I see regard changes to the GitHub actions mostly as a low risk activity.