swarmexec v1.8.1

UI
- Secrets: create a secret from the secrets tab (n) — name, multi-line value, labels
- Secrets: delete a secret from the secrets tab (d); on service removal, offer to
  delete now-orphaned secrets
- Services: remove a service from the inspect view (X)
- Contexts: guided creation — explicit SSH toggle, jump hosts, test-connection
- Fix: dialog kept focus when clicking beside a centred overlay

init
- Warn when --secret is passed but the agent secret already exists (kept, not applied)

Site
- Multilingual landing/docs (de/en/es/fr) with browser-language detection + switcher