feat(rust): the rewards — tally, kit reward, chat and the news leg (phase 13b, protocol 10)

Four event verbs and the announce leg, per PLAN.md §29:

- rust.participation.open / .collect: the plugin counts who takes part
  (seconds, kills or both, in a zone this run opened or the whole server)
  and collect files them as the run's participants, keyed by Steam id.
- rust.kit.entitle: the five recipient modes (D101), rows in the new
  rust_perm_run_grants (D84) unioned into the permission push, one extra
  use of the kit per reward as site-held credits on perm.sync (D103),
  and the rust.kit.entitled notice deferred from phase 10 (D64).
- rust.announce: one server or every server (D105).
- rust.chat announce leg, speaking only on servers whose new news switch
  is on (D104) - a card on Admin -> Rust visibility (D106).

Budgets rust.grants and rust.announcements; the kit source and four
fixed-choice sources (core has no enum param type). rust_perm_run_grants
carries core's idempotency key so a revert of a lost answer can find its
rows. Protocol 10.

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

server/test/engagement.test.js

@@ -140,9 +140,10 @@ test('the ceilings are the ones §25.2 decided', () => {
   for (const id of ['rust.clan.member.left', 'rust.clan.member.kicked', 'rust.clan.disbanded']) {
     assert.strictEqual(by[id], 'members', id)
   }
-  // D64: core's team.member.joined already covers it, and kits wait for phase 13.
+  // D64: core's team.member.joined already covers it. The kit reward waited for
+  // the phase that grants one (13b), and a reward is nobody else's news.
   assert.strictEqual(by['rust.clan.member.added'], undefined)
-  assert.strictEqual(by['rust.kit.entitled'], undefined)
+  assert.strictEqual(by['rust.kit.entitled'], 'owner')
 })
 
 test('a clan path survives core\'s url check, colons and all', () => {