feat(rust): zone presets, and the zone step's options, messages and dome (PLAN_REDESIGNS §3, D210)

Admin → Rust zone presets: named sets of ZoneManager flags and settings for
one server, several, or every server (D195), ticked in groups read from each
server's own ZoneManager list in its last hello (D211). A flag not on a
covered server is refused on save with the server named; two presets of one
name may not share a server.

rust.zone.open gains options (one line, NoBuild, radiation=10), enterMessage,
leaveMessage, delivery, dome and domeStack. The options field's dropdown is
rust.options.zone_presets, whose row VALUE is the preset's line, so picking
one copies it into the step (D210) and no published event changes when a
preset does. The line and the dome are checked against the server's hello
on save and in a dry run; bad-option and dome-unavailable are permanent.

Schema: rust_zone_presets, rust_zone_preset_servers. Swagger fragment and
routes.manifest regenerated against the pinned core f0e7d2a.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01E14m6SuuY6i1vASFeGDBeY

server/router/admin/rust.router.js

@@ -42,6 +42,10 @@ adminRustRouter.use('/config', require('./config.router'))
 // deliberately widens it, fleet-wide or for one server.
 adminRustRouter.use('/visibility', require('./visibility.router'))
 
+// Zone presets (PLAN_REDESIGNS §3.1, D195, D210): the flags and settings a zone
+// step copies, saved by name for one server, several, or the fleet.
+adminRustRouter.use('/zones', require('./zones.router'))
+
 adminRustRouter.get(
   '/servers',
   // #swagger.tags = ['Admin · Rust']