Multi-server CLI, more reverse zones, and a fix for new view directories

- CLI: name several servers and groups in the config file; select them
  with -s/--server NAME|GROUP|all|URL or JARL_SERVER. A command aimed at
  several servers is dry-run on all of them first and only runs if every
  one accepts it. Named servers always use their own token.
- Reverse zones: /32 and /128 get single-address zones; networks between
  octet or nibble boundaries (e.g. a /22) are covered by several zones
  created together, from the CLI and the web UI.
- Fix: under jarl.service's RestrictSUIDSGID, creating a view directory
  failed on chmod with the setgid bit; fall back to the permission bits.
- Web UI: the review/live switch is a small header button, and the
  pending-changes bar only shows when there are pending changes.
- TSIG key wording; the keys page points to restricted API tokens.
- Docs: several servers (cli.md), a secondary server (operations.md),
  tokens vs TSIG keys (permissions.md); CHANGELOG.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

docs/permissions.md

@@ -8,6 +8,12 @@
 | CLI, scripts, certbot | API token: `Authorization: Bearer jarl_...` | Shown once at creation, stored hashed. Optional expiry. Revocable. Last use time and IP are recorded. |
 | Root on the server | `jarld` subcommands (`init`, `user`, `import`, `adopt`, `check`, `resync`, `backup`) | Work directly on the database. They are for bootstrapping and recovery, and are audited as "local". |
 
+API tokens are how you give a script, a tool or a person limited access:
+a token restricted with grants (below) can, for example, only change TXT
+records under `_acme-challenge` in one zone. TSIG keys, on the TSIG keys page,
+are something else: shared secrets that BIND servers use to authenticate
+each other (zone transfers, NOTIFY); they don't give access to Jarl.
+
 Failed logins are rate limited: 8 per username and 20 per client IP within
 15 minutes. Failed token attempts count against the IP too. Every attempt
 is in the audit log.