Release 0.56.0

[michalharakal]

Release branch for 0.56.0 — back in lock-step with SKaiNET engine 0.56.0 (on Maven Central since 2026-09-20; the engine skipped 0.55.0 to realign the version lines).

Release commits (same shape as 0.55.0 / #433):

1. docs(changelog): 0.56.0 entry
2. docs(readme): 0.56.0 highlights and BOM coordinate
3. docs: bump version references to 0.56.0 (tutorials, Moonshine encoder reference, llm-inference/gemma/README.md)
4. release: prepare 0.56.0 -- lock-step with engine 0.56.0 (VERSION_NAME in gradle.properties)

In 0.56.0: GQA without head expansion on the tape and in StableHLO exports; structural schedule stamped by the SmolLM2/FunctionGemma export harnesses; OPTIMIZED-mode compiled JVM leg under the caller's schedule; IREE Android run-time core knob (taskTopologyGroupCount, SKAINET_TASK_GROUPS) with both libskainet_iree_redecode.so rebuilt (#424); engine 0.56.0; convention plugins 1.1.0 with jvmTarget = JVM_21 (#442); neutral hardware wording (#441); dependency bumps.

Release procedure (lessons from the engine release):

1. Merge ci(publish): manual dry run that cannot upload #443 (publish dry run) first; this branch then takes develop and is dry-run with gh workflow run publish.yml --ref release/0.56.0 — full build + signing, no upload.
2. Merge this PR with a merge commit.
3. Wait until develop CI on that merge commit has finished green.
4. Annotated tag 0.56.0 on that merge commit → publish workflow → verify on Maven Central.