feat(rust): Rust's own world events — feed, credit rule, triggers, Call a world event (PLAN_REDESIGNS §14.3.1)

The site half of stage 1, on protocol 14:

- server/worldEvents.js: the 24 types, D372's four credit rules, the grid
  from the map's geometry (none off the map), and the per-viewer reading.
- The feed serves `world.event` (a public kind): an unknown type is staff's;
  the event and its grid are public; names only for the presence audience
  (D376); Steam ids and positions only for staff (D353). A downed one carries
  `credited`/`creditedCount` by the server's rule. Client lines for all 24
  types and a World events filter.
- rust_servers.credit_rule (blow, last, most, all; default blow), set on the
  server's settings. Ingest counts heli_kills (patrol helicopters and
  Chinooks, D379) and apc_kills from `world.event` by that rule, so the line
  and Rotorbane / Tankbreaker agree. A protocol-13 tally's heliKills/apcKills
  still add as before.
- The tally's cratesHacked / dropsLooted → crates_hacked / drops_looted;
  title categories Safecracker and Scavenger (D356); leaderboard columns
  Crates hacked and Drops looted, sortable (D377).
- 24 engagement triggers rust.world.<event> (D355): ceiling everyone,
  cooldown subject the server and event (crates add where), names only.
- server/eventWorldCall.js: rust.world.call, "Call a world event"
  (risk change, reversible none, budget rust.world.calls). A position for an
  airdrop or a patrol helicopter only; the Chinook takes none (D378).

Server 585/585 (22 new in test/worldEvents.test.js), client 84/84, every
check; booted against the pinned core (43 triggers, 12 actions, 10 budgets,
20 option sources), routes.manifest unchanged at 89. Engagement manifest and
swagger fragment regenerated.

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

server/router/admin/rust.controller.js

@@ -113,6 +113,11 @@ async function putServer(req, res) {
     })
     if (schedule) await db.setSchedule(id, schedule)
 
+    // D372: written only when the save carries one, like the schedule. The router
+    // has already refused a word this build does not know.
+    const creditRule = req.body.creditRule === undefined ? null : req.body.creditRule
+    if (creditRule) await db.setCreditRule(id, creditRule)
+
     await core.activity.log({
       req,
       action: 'rust.server.save',
@@ -125,6 +130,8 @@ async function putServer(req, res) {
         // The schedule as written, when the save carried one. Nothing in it is a
         // secret, and "who moved the wipe" is a question players will ask.
         ...(schedule ? { schedule: { ...schedule, wipeOnceAt: schedule.wipeOnceAt ? schedule.wipeOnceAt.toISOString() : null } } : {}),
+        // The credit rule as written, when the save carried one (D372).
+        ...(creditRule ? { creditRule } : {}),
       },
     })