swarmexec v1.8.3

UI fixes
- Container tree: Enter on a service now toggles expand/collapse (was: opened
  its logs). Logs move to a new L key (works on a service or a container).
- Restore shelling into a container as a specific user: the container menu
  gains "Shell as user…" (name or UID[:GID]) — the TUI equivalent of exec -u.
- Closing a container shell (exit / Ctrl-D) now closes the pane; it no longer
  needs a second Esc. Only a shell that couldn't start (exit 126/127) keeps
  the pane up so the error stays readable.

Site
- Umami click tracking on the download links (per platform: linux/macOS/
  windows, each a distinct event) and the repository link.