fix(rust): nothing names who is online by default

The org lead's rule, settled 2026-09-22: who is online is always the
narrowest audience - staff - unless an operator deliberately widens it,
and a count is fine where a list of names is not.

The public site broke that in three places since phase 4. The Online
tab named every player, the feed carried joins, respawns, deaths, chat
and tallies, and the leaderboard's lastSeen - refreshed every minute by
a gather tally - said who was on as plainly as either. All three now
sit behind one setting:

* PRESENCE_KINDS, a subset of the public allowlist, gated per request.
  Below the audience the feed keeps the server's own story (wipe, start,
  shutdown) and says presenceHidden rather than looking quiet.
* the Online route answers { players: [], hidden, count, audience } -
  same shape, so an older client renders empty rather than breaking.
* rungs staff / signed_in / public, fleet-wide default in a new
  rust_settings table with an optional per-server override on
  rust_servers; an unknown stored word narrows to staff.
* the viewer's standing is RE-READ from the users row (ctx.users.getById),
  not taken from the token, so a demotion or a ban applies on the next
  request. Walked: a moderator demoted mid-session lost the roll call on
  the same cookie.
* per-viewer answers are Cache-Control: private, no-store.
* GET/PUT /admin/rust/visibility (requireRole admin) and an admin page,
  Rust visibility; every save is one activity-log row.

The browser walk also found every empty state in this module rendering
as a blank box. Core's EmptyState renders children only; this module
passed title/message (the shape the Integration Kit template teaches)
and React dropped both without a word. Fixed module-side with a small
Empty wrapper - nothing core or module-uo renders changes - and a client
test that refuses a titled EmptyState or a PageHeader subtitle.

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

server/model/events/events.model.js

@@ -51,8 +51,8 @@ function parseKinds(raw) {
  * refused: naming it in an error would confirm the kind exists, which is a small
  * thing to leak and a free one to avoid.
  */
-async function recent({ serverId, admin = false, kind = null, wipeId = null, limit }) {
-  const kinds = catalogue.kindsFor({ admin, requested: parseKinds(kind) })
+async function recent({ serverId, admin = false, presence = false, kind = null, wipeId = null, limit }) {
+  const kinds = catalogue.kindsFor({ admin, presence, requested: parseKinds(kind) })
 
   // Every requested kind was refused. Answering with an empty list is right —
   // the events they asked for are, as far as they are concerned, not there.
@@ -102,7 +102,7 @@ function shape(row) {
  * counters, so the two can never disagree — which is the whole reason R12's
  * "per-wipe detail plus all-time rollups" is one table and not two.
  */
-async function leaderboard({ serverId, wipeId = null, sort = 'kills', limit }) {
+async function leaderboard({ serverId, wipeId = null, sort = 'kills', limit, presence = false }) {
   const rows = await db.leaderboard({
     serverId,
     wipeId,
@@ -118,7 +118,11 @@ async function leaderboard({ serverId, wipeId = null, sort = 'kills', limit }) {
     npcKills: Number(r.npcKills) || 0,
     structures: Number(r.structures) || 0,
     playtimeSec: Number(r.playtimeSec) || 0,
-    lastSeen: r.lastSeen || null,
+    // Withheld below the presence audience. A tally refreshes it every minute a
+    // player is on, so a `lastSeen` of forty seconds ago is the Online tab by
+    // another name. The ORDER still uses it as a tie-break — that says who was
+    // on more recently, never whether anybody is on now.
+    ...(presence ? { lastSeen: r.lastSeen || null } : {}),
   }))
 }