fix: add F-Droid changelog and remove binary test fixtures

[najuna-brian]

Pull Request Title

Description

• Add changelogs/2.txt for F-Droid Fastlane metadata
• Remove valid_bundle01.zip and valid_bundle02.zip from synkronus test data
• Remove affected test cases that depended on those binary fixtures

All remaining tests pass. Binary test fixtures will be replaced with
a script that generates them at test time (tracked separately).

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Testing

• Unit tests added/updated
• Integration tests added/updated
• Manually tested
• Tested on multiple platforms (if applicable)
• Not applicable

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Breaking Changes

• This PR introduces breaking changes
• This PR does NOT introduce breaking changes

If breaking changes, please describe migration steps:

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Documentation Updates

• Documentation has been updated
• Documentation update is not required

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Checklist

• Code follows project style guidelines
• All existing tests pass
• New tests added for new functionality
• PR title follows Conventional Commits format

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Thank you for contributing to Open Data Ensemble (ODE)!

[r0ssing]

LGTM