Disable zones instead of deleting them

A disabled zone stays in Jarl with its records, options and history,
still editable, but named doesn't load it; enabling it serves it as it is
then. Signed zones, and zones another view shares, can't be disabled.
jarl zone disable|enable, the zone page's Disable/Enable button.
Database schema 7.

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

docs/api.md

@@ -160,7 +160,7 @@ may be the name.
 | GET | `/zones` | `?view=`, `?type=`, `?q=` (name contains) |
 | POST | `/zones` | ZoneInput (below) |
 | GET | `/zones/{zone}` | |
-| PATCH | `/zones/{zone}` | ZoneInput (only the fields to change) |
+| PATCH | `/zones/{zone}` | ZoneInput (only the fields to change); `{"disabled": true}` disables the zone: named stops loading it, Jarl keeps it |
 | DELETE | `/zones/{zone}` | deletes the zone with its records and options |
 | GET | `/zones/{zone}/file` | the generated zone file (text/plain) |
 | GET | `/zones/{zone}/serials` | asks the zone's other name servers for their serial (below) |

docs/cli.md

@@ -182,12 +182,21 @@ jarl zone create consul --type forward --forwarder "127.0.0.1 port 8600"
 jarl zone update adbraun.lol --ttl 3600 --contact hostmaster@adbraun.lol --refresh 7200
 jarl zone update adbraun.lol --move-to-view internal
 jarl zone delete lab.adbraun.lol [-y]
+jarl zone disable lab.adbraun.lol [--view V]   # named stops serving it; kept (and editable) in Jarl
+jarl zone enable lab.adbraun.lol [--view V]
 jarl zone file adbraun.lol                             # the generated zone file
 jarl zone import adbraun.lol db.adbraun.lol [--replace] [--use-soa]
 jarl zone serials adbraun.lol                          # are the secondaries (or primaries) on the current serial?
 jarl zone delegation adbraun.lol [--resolver 9.9.9.9]  # does the parent zone delegate it correctly?
 ```
 
+**Disabling a zone** leaves it out of named's configuration but keeps it in
+Jarl: records, options and history, which can still be edited. Its names
+are then answered by recursion where the view offers it (the internet's
+version of the zone, if any), and REFUSED elsewhere; `disable` says which.
+Enabling it serves it as it is then. A signed zone can't be disabled (turn
+signing off first), nor a zone another view shares with `in-view`.
+
 Reverse names follow the dots (the nibbles in IPv6), so a reverse zone
 covers a /8, /16 or /24 (a multiple of /4 for IPv6). A network in between is
 covered by several zones, created together in one changeset: a /22 by four

docs/validation.md

@@ -57,6 +57,8 @@ showing them.
 | `zone_missing_option` | error | Secondary, stub and mirror zones need `primaries` |
 | `zone_file_required` / `zone_file_invalid` / `zone_file_managed` | error | Hint zones need a file. Forward zones have none. Primary zone files are Jarl's |
 | `zone_inview_invalid`, `zone_inview_option` | error | `in-view` zones only inside views, and only with `forward`/`forwarders` |
+| `zone_inview_disabled` | error | An `in-view` zone can't share a disabled zone |
+| `zone_disabled_signed` | error | A signed zone can't be disabled: turn signing off first |
 | `zone_records_unmanaged` | error | Only primary zones can have records in Jarl |
 | `zone_serial_policy` | error | `date`, `increment` or `unixtime` |
 | `zone_no_forwarders`, `zone_hint_name`, `zone_name_slash` | info / warning | Unusual but legal setups |