test: add tests for all new features, fix bugs found by tests
- integration: logs query flags, hosts command, peer command sections
- unit: fmt::bytes, config::dns_string, parse_since, ui::group::status
- destructive: duplicate rule validation, peer update-dns/tunnel
- fix: config::allowed_ips_for used $2 instead of $1
- fix: identity rule assign exit_code unbound variable
- fix: ctx::identity → ctx::identities in peers::get_identity
- fix: peers::get_identity restored (needed for rule assign duplicate check)
- rule assign: blocks if rule already in peer's identity via peers::get_identity
- identity rule assign: --migrate removes conflicting direct peer rules
cf71e9f51a