The host admin socket path was duplicated on every daemon-assisted verb
(agents restart/restart-all, stop, start). Hoist it to a single global arg
on the top-level Cli (`--socket`, default DEFAULT_HOST_SOCKET, accepted
before or after the subcommand) and thread cli.socket through dispatch.
Verbs that don't talk to the daemon ignore it. Pure CLI-ergonomics change;
no wire/behaviour change. Regenerated docs/tools/hivectl-cli.md.
The hivectl-docs flake check regenerates docs/tools/hivectl-cli.md from the
clap command tree and asserts it's committed up to date. Adding the stop/start
verbs changed the CLI, so the doc was stale and the check failed. Regenerate it.
