divekit update

Planned: Check for new CLI versions and perform updates.

Status: Planned

The divekit update command is planned but not yet implemented in the current CLI. When implemented, this command is intended to:

Check the currently installed Divekit CLI version
Compare against the latest available release
Offer a non-interactive flag to auto-apply updates
Provide clear logs and exit codes suitable for CI usage

Planned flags (subject to change):

-y, --yes — Auto-confirm applying an available update
--check — Only check and print the current/latest versions without applying

Current approach:

Download the latest binary from the releases page and re-run divekit install
Verify installation with:
```
divekit --version
```

Release downloads:

https://gitlab.git.nrw/divekit/divekit-cli/-/tags

Last modified September 11, 2025: docs(cli): update documentation to ~current state (9bc308b)