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>

scripts/e2e.sh

@@ -410,6 +410,22 @@ run "wipe the child" 0 $J zone dnssec wipe sub.adbraun.test --view external --ye
 run "delete the child" 0 $J zone delete sub.adbraun.test --view external --yes
 run "remove the delegation" 0 $J record delete adbraun.test sub NS --view external --yes
 
+# Disabled zones: kept in Jarl, not loaded by named.
+run "zone for disabling" 0 $J zone create parked.test --view internal --ns ns1.adbraun.test.
+run "record in it" 0 $J record add parked.test www A 192.0.2.70 --view internal
+expect_dig "parked www served" "192.0.2.70" www.parked.test A
+run "zone disable" 0 $J zone disable parked.test --view internal
+contains "recursion"
+expect_dig "disabled zone not served" "" www.parked.test A
+run "named.conf says it's disabled" 0 grep -q 'zone "parked.test" is disabled in Jarl' $E/etc-jarl/named.conf
+run "zone list marks it" 0 $J zone list
+contains "parked.test.*primary (disabled)"
+run "editing a disabled zone works (no reload of a zone named lacks)" 0 $J record add parked.test api A 192.0.2.71 --view internal
+run "zone enable" 0 $J zone enable parked.test --view internal
+expect_dig "enabled zone served again" "192.0.2.70" www.parked.test A
+expect_dig "with the change made while disabled" "192.0.2.71" api.parked.test A
+run "delete it" 0 $J zone delete parked.test --view internal --yes
+
 # Blocking (docs/blocking.md). It only changes answers to recursive
 # queries, so these ask with recursion and look at which policy zone (if
 # any) the answer came from.