refactor(persistence): migrate bridge events file to canonical atomic-write util (DC-104) [glm-grade=A]

writeEvents() in scripts/stripe-license-bridge.js drops its private
tmp+writeFileSync+rename copy (no fsync, Date.now() tmp names) and
delegates to src/utils/atomic-write.js atomicWriteJSON (exclusive-create
tmp, fsync, rename, parent-dir fsync, 0600). stripe-events.json is the
Stripe webhook idempotency log - a torn write silently drops event-ids,
so a Stripe retry re-runs delivery (duplicate license email; combined
with a torn fulfillment record, a duplicate key mint). readEvents is
JSON.parse-only, so the canonical serializer's trailing-newline drop is
unobservable. Sole writer confirmed by grep. +2 DC-104 pins: full
recordEvent->eventSeen dedupe cycle (0600/complete JSON/zero-leftovers)
and 8-step back-to-back mutation parse-complete check. 121 suites /
2778 tests green.

Judge: GLM-5.3 round-1 A (deleg_e8e1f9d0), URN urn:ump:frwh34wtlsunsymok6pzyujyehq6ikpvadypmsg7ndk7jjvzrp5a

dashcaddy-api/scripts/stripe-license-bridge.js

@@ -105,6 +105,7 @@ const fs = require('fs');
 const path = require('path');
 const { generateCodes, loadSecret } = require('../license-keygen');
 const platformPaths = require('../platform-paths');
+const { atomicWriteJSON } = require('../src/utils/atomic-write');
 const catalog = require('../src/billing/catalog');
 const invoice = require('../src/billing/invoice');
 const { createFulfillmentStore, DELIVERY_LEASE_MS } = require('../src/billing/fulfillment-store');
@@ -220,10 +221,11 @@ function readEvents() {
 }
 
 function writeEvents(state) {
-  // Atomic write: tmp + rename.
-  const tmp = `${EVENTS_FILE}.tmp.${process.pid}.${Date.now()}`;
-  fs.writeFileSync(tmp, JSON.stringify(state, null, 2) + '\n', { mode: 0o600 });
-  fs.renameSync(tmp, EVENTS_FILE);
+  // Canonical atomic writer (DC-099/DC-104): exclusive-create tmp + fsync +
+  // rename + parent-dir fsync, 0600. Replaces the private tmp+rename copy —
+  // a torn stripe-events.json silently drops event-ids, which makes a
+  // Stripe retry re-run delivery (duplicate license email / duplicate key).
+  atomicWriteJSON(EVENTS_FILE, state, { mode: 0o600 });
 }
 
 function recordEvent(eventId, meta) {