Publish python-multiplatform-compose to Maven Central; fix stale Android libs and the getting-started snippet #379

An outside-consumer check of the alpha03 bundle found: python-multiplatform-compose (PythonAppView host) not published; a locally built AAR carries stale libpython3.14 libraries; getting-started section 04 does not run as written (missing Kotlin version, target, role.set("app"), upcall bootstrap) and still says no release is published. Done when: compose publishes with the others, the bundle check rejects foreign libpython versions, and the guide snippet runs.