release: bump version to 0.23.4

Transformers-only release on the 0.23.x line; no SKaiNET engine bump.
Highlights since 0.23.3:

  - fix(bom): :llm-inference:apertus and :llm-inference:voxtral were
    publishing to Maven Central but missing from the BOM. Consumers
    using these modules through the BOM now get version alignment.

  - fix(docs): README and the two tutorial pages were showing the
    project paths (`llm-core`, `llm-runtime-kllama`, `llm-agent`) as
    if they were published artifact IDs. Real coordinates are
    `skainet-transformers-core` etc. — anyone copy-pasting hit
    "module not found". Snippets now use the BOM pattern.

  - build(bom): the BOM constraint list is no longer hand-maintained.
    A small convention plugin in `buildSrc/`
    (`sk.ainet.transformers.bom-coverage`) auto-discovers every
    sibling subproject that applies `com.vanniktech.maven.publish`
    and adds it as an api constraint. Only manual input is the
    exclusion list (currently just `:llm-performance`). The BOM is
    coherent by construction — drift can no longer happen.

  - build(test-java): `llm-test-java` consumes SKaiNET via the local
    BOM so the BOM is exercised inside the build itself.

  - build: dead `allprojects { group = "sk.ainet.llm" }` removed;
    the GROUP property in `gradle.properties` is now the only source
    of truth for the in-memory project group.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

Author: michalharakal

gradle.properties

@@ -1,5 +1,5 @@
 GROUP=sk.ainet.transformers
-VERSION_NAME=0.23.3
+VERSION_NAME=0.23.4
 
 POM_DESCRIPTION=SKaiNET-transformers