fix(rust): send reward notices, and keep a downed line's credit rule (W21, W4)

W21: the permission push named its fields one by one and left out
`notices`, so no kit reward, lend or give ever told its player
anything (D333). The body is now built by `pushBody`, which carries
every field the payload has; a test fails if a payload field is
dropped again.

W4: a downed patrol helicopter, Chinook or Bradley is stored with the
credit rule in force when it arrived, and the feed reads that stamp.
Before, the line re-credited past rows with the server's current rule
while the Rotorbane/Tankbreaker counts kept the old one. Rows stored
before this change keep today's reading.

PLAN_LAST_FIXES.md stage 1.

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

server/test/worldEvents.test.js

@@ -216,6 +216,19 @@ test('a Bradley counts toward Tankbreaker, and an arrival counts nothing', async
   assert.strictEqual(rec2.touching('rust_player_wipe_stats').length, 0)
 })
 
+test('a downed one is stored with the rule that credited it; an arrival is stored as sent (W4)', async () => {
+  const { apply } = require('../ingest')
+  const storedRaw = async (frame) => {
+    const rec = withRecorder()
+    await apply('main', { id: 1, kind: 'world.event', frame }, { id: 'main', creditRule: 'all' })
+    const insert = rec.touching('rust_events').find((s) => /INSERT/i.test(s.sql))
+    return JSON.parse(insert.params.find((p) => typeof p === 'string' && p.startsWith('{')))
+  }
+
+  assert.strictEqual((await storedRaw(downed())).creditRule, 'all')
+  assert.strictEqual((await storedRaw(world('heli.arrived', { x: 1, z: 1 }))).creditRule, undefined)
+})
+
 test('the tally’s crates hacked and drops looted are added up (D356)', async () => {
   const rec = withRecorder()
   const { apply } = require('../ingest')
@@ -251,6 +264,21 @@ test('the feed reads each world event for its viewer, with the server’s rule a
   assert.deepStrictEqual(member.frame.credited, [{ name: 'Bob' }])
 })
 
+test('a line keeps the rule it was stored with after the server’s rule changes (W4)', async () => {
+  const stamped = downed({ creditRule: 'all' })
+  withRecorder((sql) => {
+    if (sql.includes('FROM rust_events')) return [{ id: 9, kind: 'world.event', t: NOW, wipeId: 'w1', steamId: null, raw: JSON.stringify(stamped) }]
+    if (sql.includes('FROM rust_servers')) return [{ id: 'main', name: 'Main', creditRule: 'most', enabled: 1 }]
+    return []
+  })
+  const events = require('../model/events/events.model')
+
+  const [member] = await events.recent({ serverId: 'main', presence: true })
+  assert.strictEqual(member.frame.creditRule, 'all')
+  assert.strictEqual(member.frame.creditedCount, 2)
+  assert.deepStrictEqual(member.frame.credited.map((c) => c.name).sort(), ['Alice', 'Bob'])
+})
+
 // ── Triggers (D355) ────────────────────────────────────────────────────────
 
 test('one public trigger per type, none of them declaring a Steam id', () => {