kn: fix CI and add documents for building script

[isning]

This pull request had done following things:

1. Switched cinterop to use built header files rather than source headers to avoid failure of finding building artifact Version.h.
2. Introduced zig for providing sysroot for building linux targets and build shared libraries for them. This allows us to reuse the generated header files and run tests against the resulting dynamic libraries. But it's notable that we still do NOT ship shared libraries for linux targets.
3. Moved content of libZXing.def to build.gradle.kts.
4. Fixed invalid strictEnums configuration in libZXing.def before.

Although Zig is often described as “another language compatible with C,” in this context we only use it for the cross-compilation sysroot it provides, in order to build Linux targets. In practice, it is essentially a wrapper around Clang, combined with a set of tools that handle tasks such as downloading and managing sysroots. It also makes it easy to specify details like the glibc version used by the sysroot.

Otherwise, we would have to maintain the sysroot ourselves and handle compilation for architectures such as ARM64. Given the fragmented nature of the Linux ecosystem, this would likely be quite cumbersome.

[Copilot]

Pull request overview

Updates the Kotlin/Native wrapper and CI to improve Linux testing/linking and align the wrapper API with the current ZXing C API.

Changes:

• Refactors Kotlin/Native barcode format interop (switching from raw bitmask parsing to enum/value mapping and updating reader options formats getter/setter).
• Moves cinterop configuration from libZXing.def into Gradle and adjusts Linux CI to build/test against shared libraries via Zig.
• Tweaks CI workflows and ignores additional Kotlin tooling artifacts.

Reviewed changes

Copilot reviewed 9 out of 9 changed files in this pull request and generated 3 comments.

Show a summary per file

File	Description
wrappers/kn/src/nativeMain/kotlin/zxingcpp/BarcodeWriter.kt	Updates creator options format interop to use the new cValue mapping.
wrappers/kn/src/nativeMain/kotlin/zxingcpp/BarcodeReader.kt	Reworks ReaderOptions.formats interop to use list + count API and pinned arrays.
wrappers/kn/src/nativeMain/kotlin/zxingcpp/BarcodeFormat.kt	Refactors BarcodeFormat to wrap ZXing_BarcodeFormat and adds conversion helpers.
wrappers/kn/src/nativeMain/kotlin/zxingcpp/Barcode.kt	Simplifies barcode format mapping via toKObject().
wrappers/kn/build.gradle.kts	Embeds cinterop config in Gradle and configures Linux tests to use shared libs; adds Zig-based builds for Linux.
wrappers/kn/.gitignore	Ignores .kotlin directory.
.github/workflows/publish-kn.yml	Removes prebuilt linux artifact dependency; installs Zig; uploads built Linux shared libs.
.github/workflows/ci.yml	Removes system lib install step; installs Zig; updates konan version.

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[Copilot]

Pull request overview

Copilot reviewed 10 out of 10 changed files in this pull request and generated 2 comments.

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[Copilot]

LD_LIBRARY_PATH is being set to just soPath, which overwrites any existing LD_LIBRARY_PATH value for the test process. This can break environments that rely on additional shared-library search paths (including CI runners and developer machines). Prefer prepending/appending soPath to the existing value (and handle the empty/null case) rather than replacing it outright.

[axxel]

Could you do me the favor and resolve the merge conflicts?

[isning]

confilict resolved :)

[axxel]

Unfortunately, the publish-kn job failed to publish the results: https://github.com/axxel/zxing-cpp/actions/runs/14321812223

Could you have a look at this? Note that my lengthy work on fixing the publication of the android artifacts was apparently successful. Maybe there is some insight to have.

[isning]

Unfortunately, the publish-kn job failed to publish the results: https://github.com/axxel/zxing-cpp/actions/runs/14321812223

Could you have a look at this? Note that my lengthy work on fixing the publication of the android artifacts was apparently successful. Maybe there is some insight to have.

Sorry but I cant access the workflow's log for it says "The logs for this run have expired and are no longer available."
Do you have any idea about this?

[axxel]

My bad, I sent you the wrong link. Here is the right one: https://github.com/zxing-cpp/zxing-cpp/actions/runs/21869699416