Restore Coveralls and cover runtime entry points

[Frotty]

Summary

• restore Coveralls uploads from GitHub Actions using the official v2 action and JaCoCo XML
• generate the Linux coverage report in the same Gradle invocation that runs tests, avoiding a second suite run
• remove the dormant legacy Gradle Coveralls plugin
• exclude generated IR/AST code, the concrete Swing UI, and behaviorless signaling exceptions; compiler, language-server, map, and utility logic remain accountable
• add focused coverage for checksum manifests, the CLI entry point, compilation-server lifecycle, and cached map imports
• make checksum manifests deterministic across filesystems and make the compilation server testable on an ephemeral port
• fix the newly exposed -version CLI parsing bug

Root cause

The GitHub Actions workflow only ran test. It never ran jacocoTestReport, the old Gradle coveralls task, or a Coveralls upload action, so coverage stopped updating after the previous CI migration.

The old Coveralls screenshot is also stale: the hotdoc package is gone, CompilationProcess already has direct Lua tests, and this PR covers the remaining meaningful zero-coverage runtime areas instead of adding constructor-only tests for marker exceptions.

Focused verification

• ./gradlew.bat test --tests "tests.wurstscript.tests.ChecksumsTests" --tests "de.peeeq.wurstio.MainTests" --tests "de.peeeq.wurstio.compilationserver.WurstServerTests" --tests "de.peeeq.wurstio.map.importer.ImportFileTests" --tests "de.peeeq.wurstio.CompilationProcessLuaTests": passed (12 tests)
• ./gradlew.bat test --tests "de.peeeq.wurstio.MainTests": passed after strengthening the help assertion
• ./gradlew.bat jacocoTestReport -x test: passed using focused execution data
• focused instruction coverage: Checksums 91.2%, ImportFile 61.4%, WurstServer 28.9%, Main 14.8%
• generated XML excludes de/peeeq/wurstio/gui and the two marker exceptions while retaining de/peeeq/wurstscript/gui

The complete suite and live Coveralls upload are left to this PR's Linux CI job.

[chatgpt-codex-connector]

Codex Review Summary

This comment shows the latest Codex review activity on this pull request.

Review	Status	Commit	Review trigger
📝 Code Review	✅ Completed 2026-08-29T22:29:14.019366Z	ddf718c	Manual request

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[coveralls]

Coverage is 71.092% — codex/restore-coveralls-coverage into master. No base build found for master.

[Frotty]

@codex review

[chatgpt-codex-connector]

Codex Review: Didn't find any major issues. 🚀

Reviewed commit: ddf718c18c

ℹ️ About Codex in GitHub

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• Open a pull request for review
• Mark a draft as ready
• Comment "@codex review".

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