Add automated ABI and published-coordinate compatibility checks

[easyhooon]

Summary

Add automated compatibility checks for dari-core so Kotlin Multiplatform publication changes cannot silently break existing Android consumers.

Motivation

PR #88 moves dari-core from a single Android AAR to Kotlin Multiplatform publications. Its source-level smoke tests and manual AAR comparison provide useful confidence, but CI does not currently:

• compare the generated Android/JVM ABI with a stable baseline or the latest released artifact;
• compile a clean external Android consumer that resolves the existing io.github.easyhooon:dari-core:<version> coordinate from a locally published repository.

This follows up on the API compatibility requirement in #13.

Proposed Approach

• Add an ABI baseline/check using a suitable tool such as Kotlin Binary Compatibility Validator, Metalava, or JApiCmp.
• Publish dari-core to an isolated local Maven repository with publication signing disabled.
• Add a minimal external Android consumer that depends on the legacy root coordinate.
• Verify that Gradle metadata selects the dari-core-android variant and that the consumer compiles.
• Run these checks when dari-core, Gradle configuration, or publication configuration changes.

Acceptance Criteria

• CI fails when an existing public Android/JVM signature is removed or changed incompatibly.
• A clean Android consumer compiles against io.github.easyhooon:dari-core:<version> from the generated local repository.
• The test does not rely on project dependencies that bypass published metadata.
• The compatibility workflow is documented and runs without release signing credentials.

Related

• KMP (Kotlin Multiplatform) Support #13
• feat: add KMP support to dari-core #88