Empty changelog + versioning UX issues + minor nits after v0.14.0b2 release to stable channel

The just released v0.14.0b2 on Play Store includes a short summary of changes which links to a "full changelog" which was (1) a draft unpublished release, invisible to others likely and (2) empty description. I was expecting a similarly generated release description as used for the main ActivityWatch and gptme repos (should probably share/copy their script with reference or wget it from those repos + run in CI job like they do).

Also, the bottom "Version: v0.14.0 (rust)" in the webui is misleading (should be `v0.14.0b2` not what it happened to say in the Cargo.toml for aw-server-rust, it should be overridden with the *release version* not the component version - which doesn't even include a submodule commit or anything so it's not that precise anyway)

The webui is missing some margin/padding right above the "Made with <3 by the ActivityWatch developers", at least on small screens. Prob due to the `my-sm-3` class which should probably also have `mb-3` to fix so the bottom margin remains (the top should indeed go).

@TimeToBuildBob Go