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

client/src/routes/admin/ServerSettings.jsx

@@ -38,6 +38,16 @@ const RULES = [
   { id: 'biweekly', label: 'Every other week', hint: 'Every second week, on the weeks the date below falls in, and the forced wipe.' },
 ]
 
+// Who a downed patrol helicopter, Chinook or Bradley credits (protocol 14, D372).
+// The same rule writes the feed line and the Rotorbane / Tankbreaker counts; the
+// server's own list, mirrored here so the form needs no round trip.
+const CREDIT_RULES = [
+  { id: 'blow', label: 'Killing blow', hint: 'The player whose hit destroyed it — for the patrol helicopter, the crippling hit, else the last hit. The default.' },
+  { id: 'last', label: 'Last hit', hint: 'The last player to hurt it.' },
+  { id: 'most', label: 'Most damage', hint: 'The player who dealt it the most damage.' },
+  { id: 'all', label: 'Everyone who hurt it', hint: 'Every player who damaged it, one each.' },
+]
+
 const DAYS = ['Sunday', 'Monday', 'Tuesday', 'Wednesday', 'Thursday', 'Friday', 'Saturday']
 
 const SOURCE = { forced: 'the forced wipe', rule: 'its own schedule', once: 'the one-off date' }
@@ -110,6 +120,7 @@ function blankForm() {
     wipeTz: localZone(),
     wipeAnchor: '',
     wipeOnce: '',
+    creditRule: 'blow',
   }
 }
 
@@ -131,6 +142,7 @@ function formFrom(server) {
     wipeAnchor: s.anchor || '',
     wipeOnce: toLocalInput(s.onceAt),
     storedOnceAt: s.onceAt || null,
+    creditRule: server.creditRule || 'blow',
   }
 }
 
@@ -155,6 +167,7 @@ function bodyFrom(form) {
       ? null
       : new Date(form.wipeOnce).toISOString(),
   }
+  if (form.creditRule) body.creditRule = form.creditRule
   if (form.sidecarToken) body.sidecarToken = form.sidecarToken
   if (form.protocol !== undefined) body.protocol = form.protocol
   return body
@@ -409,6 +422,17 @@ function ServerForm({ form, set, busy, error, onSave, onCancel }) {
           </p>
         )}
       </fieldset>
+      <fieldset style={{ border: '1px solid var(--line-soft)', borderRadius: 8, padding: '12px 14px', display: 'grid', gap: 12 }}>
+        <legend className="sans" style={{ color: 'var(--head)', fontSize: '0.86rem', padding: '0 6px' }}>World events</legend>
+        <Field
+          label="Who downs a helicopter or a Bradley"
+          hint={`${(CREDIT_RULES.find((r) => r.id === form.creditRule) || CREDIT_RULES[0]).hint} It names them in the feed and counts toward Rotorbane and Tankbreaker, from now on.`}
+        >
+          <select value={form.creditRule} onChange={set('creditRule')} style={inputStyle}>
+            {CREDIT_RULES.map((r) => <option key={r.id} value={r.id}>{r.label}</option>)}
+          </select>
+        </Field>
+      </fieldset>
       <datalist id="rust-zones">{ZONES.map((z) => <option key={z} value={z} />)}</datalist>
 
       <div className="sans" style={{ display: 'flex', alignItems: 'center', gap: 12 }}>