CATROID-1654 Fix startup crash by hardening project parsing and room upgrade

[wslany]

Summary
This PR prevents startup crashes after app updates in two related startup paths:

1. malformed legacy project metadata (code.xml)
2. legacy featured-project cache database schema mismatch

https://catrobat.atlassian.net/browse/CATROID-1654

What changed

1. Added regression tests for invalid metadata parsing in ProjectMetaDataParserTest.

2. Hardened ProjectMetaDataParser to:

   • reject missing/blank programName
   • convert runtime parse failures into IOException consistently

3. Hardened startup project scan in MainFragmentViewModel:

   • catch and skip metadata parse failures (IOException)
   • include metadata file path in log output

4. Added Room database upgrade handling for featured-project cache data:

   • bumped AppDatabase version 2 -> 3
   • added MIGRATION_2_3 and wired it in Koin database builder
   • migration safely rebuilds cache/synced tables (featured_project, project_response, project_category)
   • added migration regression test and schema 3.json

Why
On upgraded installs with legacy/corrupted project metadata, startup scan could fail before the user reaches the main UI.
Additionally, some upgraded installs had a legacy Room identity hash (c60ebf...) while current code expects (2d6dd...), causing startup termination when opening the featured-project cache DB.

Behavior after fix

App startup remains stable even if one or more project metadata files are broken.
Broken project metadata entries are skipped; valid projects still load.
Featured-project cache DB is migrated/rebuilt on upgrade without deleting user projects.

Testing

:catroid:testCatroidDebugUnitTest --tests "org.catrobat.catroid.test.content.backwardcompatibility.ProjectMetaDataParserTest" --no-daemon
:catroid:testCatroidDebugUnitTest --tests "org.catrobat.catroid.test.content.backwardcompatibility.*" --no-daemon
:catroid:testCatroidDebugUnitTest --tests "org.catrobat.catroid.db.DatabaseMigrationsTest" --no-daemon

Your checklist for this pull request

Please review the contributing guidelines and wiki pages of this repository.

• Include the name of the Jira ticket in the PR's title
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• Choose the proper base branch (release-1.4.0)
• Confirm that the changes follow the project's coding guidelines
• Verify that the changes generate no compiler or linter warnings
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• Include reasonable and readable tests verifying the added or changed behavior
• Confirm that new and existing unit tests pass locally
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[Copilot]

Pull request overview

Hardens legacy code.xml project metadata parsing to prevent app startup crashes when encountering malformed or corrupted project metadata after upgrades.

Changes:

• Added unit tests for invalid/missing programName handling in legacy metadata parsing.
• Updated ProjectMetaDataParser to validate programName and normalize runtime parsing failures into IOException.
• Updated startup project scan in MainFragmentViewModel to skip/log projects whose metadata cannot be parsed (including file path in logs).

Reviewed changes

Copilot reviewed 3 out of 3 changed files in this pull request and generated 3 comments.

File	Description
catroid/src/test/java/org/catrobat/catroid/test/content/backwardcompatibility/ProjectMetaDataParserTest.java	Adds regression tests for invalid metadata inputs (missing/blank programName).
catroid/src/main/java/org/catrobat/catroid/ui/recyclerview/viewmodel/MainFragmentViewModel.kt	Hardens startup scan by catching parsing failures and logging the failing metadata path.
catroid/src/main/java/org/catrobat/catroid/content/backwardcompatibility/ProjectMetaDataParser.java	Adds validation for required fields and wraps runtime XStream parse failures into IOException.

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[wslany]

I investigated the device crash log from the update-repro setup and found a second startup crash that is separate from the project XML parsing fix.

Root cause from logcat:

• IllegalStateException: Room cannot verify the data integrity
• expected identity hash: 2d6dd2073b5265cd9e3920e29b07c537
• found: c60ebf67428479ff4619d56d1eb30d08

This happens in AppDatabase when opening project_response/featured cache tables. It is an old schema (without private) being opened by code expecting the newer schema.

I pushed a follow-up on this PR branch:

• [test] add migration regression test
• [fix] bump AppDatabase to version 3 + add MIGRATION_2_3 that rebuilds featured-project cache tables safely
• wire migration in Koin builder
• add Room schema file 3.json

This migration only rebuilds synced/cache data tables, not user projects, so it should prevent startup crash on update without requiring full app data deletion.

[Copilot]

Pull request overview

Copilot reviewed 8 out of 8 changed files in this pull request and generated 2 comments.

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[Copilot]

Pull request overview

Copilot reviewed 8 out of 8 changed files in this pull request and generated 1 comment.

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[wslany]

I confirmed the crash before the fix consistently on my phone, then updated to the fixed version (with the same package name) and observed no crash anymore. I also tested the fixed APK along other aspects and found no obvious deficiencies.

[reichli]

I only found one problem with a test that I could not run.

The rest of the PR looks good! Database migration + tests look good.
I was also able to reproduce the crash and fix it with this PR.

[sonarqubecloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud

[reichli]

Approved - thank you very much!