fix(quick-260610-i4x-01): replace node-cron schedule() with setInterval in three broker workers

- poller.ts: setInterval(cb, 5 * 60 * 1000) replaces schedule('*/5 * * * *', cb)
- outboxWorker.ts: setInterval(cb, 15 * 1000) replaces schedule('*/15 * * * * *', cb)
- reminderScheduler.ts: setInterval(cb, 60 * 1000) replaces schedule('* * * * *', cb)
- Remove 'import { schedule } from node-cron' from all three files
- Update doc comments to reflect setInterval and document why (node-cron 4.2.1 silent skip)
- Callback bodies and .catch wrappers unchanged; typecheck clean; 91/91 broker tests pass

apps/api/src/broker/outboxWorker.ts

@@ -17,13 +17,12 @@
  * T-03-14: create-before-delete ordering; create-fail aborts delete.
  *
  * runOutboxDrain is exported for unit testing.
- * startOutboxWorker wraps it in a 15-second node-cron schedule.
+ * startOutboxWorker wraps it in a 15-second setInterval.
+ * (node-cron 4.2.1 silently skipped scheduled executions in the long-running server process;
+ * setInterval fires reliably in the same process — replaced to fix the silent skip.)
  *
  * Source: poller.ts pattern (runPoll/startBrokerPoller)
- * Source: https://github.com/node-cron/node-cron (v4 stable)
  */
-
-import { schedule } from 'node-cron'
 import { z } from 'zod'
 import { and, eq, lte } from 'drizzle-orm'
 import { db } from '../db/client.js'
@@ -752,11 +751,13 @@ export async function runOutboxDrain(): Promise<void> {
 /**
  * Starts the 15-second background outbox drain schedule.
  * Call once at API startup (wired in index.ts beside startBrokerPoller).
+ * Uses setInterval instead of node-cron: node-cron 4.2.1 silently skipped executions
+ * in the long-running server process; setInterval fires reliably.
  */
 export function startOutboxWorker(): void {
-  schedule('*/15 * * * * *', () => {
+  setInterval(() => {
     runOutboxDrain().catch((err: unknown) => {
       console.error('[outboxWorker] Unhandled runOutboxDrain error:', err)
     })
-  })
+  }, 15 * 1000)
 }

apps/api/src/broker/poller.ts

@@ -1,5 +1,5 @@
 /**
- * CalDAV broker poller — runs every 5 minutes via node-cron.
+ * CalDAV broker poller — runs every 5 minutes via setInterval.
  *
  * Responsibilities (D-13, D-02):
  *   - Load all member_credentials (N-credential per-member model)
@@ -10,12 +10,10 @@
  *       → ctag changed or null: call syncCalendar (REPORT → ical.js → DB upsert)
  *
  * runPoll is exported for unit testing (inject mocks via vi.mock at the module level).
- * startBrokerPoller wraps it in node-cron's 5-minute schedule.
- *
- * Source: https://github.com/node-cron/node-cron (v4 stable basic API)
+ * startBrokerPoller wraps it in a 5-minute setInterval.
+ * (node-cron 4.2.1 silently skipped scheduled executions in the long-running server process;
+ * setInterval fires reliably in the same process — replaced to fix the silent skip.)
  */
-
-import { schedule } from 'node-cron'
 import { and, eq } from 'drizzle-orm'
 import { db } from '../db/client.js'
 import { memberCredentials, calendars } from '../db/schema.js'
@@ -91,11 +89,13 @@ export async function runPoll(): Promise<void> {
 /**
  * Starts the 5-minute background polling schedule.
  * Call once at API startup (Plan 04 wires this into index.ts).
+ * Uses setInterval instead of node-cron: node-cron 4.2.1 silently skipped executions
+ * in the long-running server process; setInterval fires reliably.
  */
 export function startBrokerPoller(): void {
-  schedule('*/5 * * * *', () => {
+  setInterval(() => {
     runPoll().catch((err: unknown) => {
       console.error('[broker/poller] Unhandled runPoll error:', err)
     })
-  })
+  }, 5 * 60 * 1000)
 }

apps/api/src/broker/reminderScheduler.ts

@@ -1,7 +1,9 @@
 /**
  * Reminder scheduler — shared-timed-event 15-min reminder scan.
  *
- * Fires every minute via node-cron.  Each tick calls runReminderCheck() which:
+ * Fires every minute via setInterval.  Each tick calls runReminderCheck() which:
+ * (node-cron 4.2.1 silently skipped scheduled executions in the long-running server
+ * process; setInterval fires reliably in the same process — replaced to fix the silent skip.)
  *   1. Queries shared (isShared=true) timed (allDay=false) events whose dtstartUtc
  *      falls in (now, now+16min] — strictly after now (future only; excludes
  *      already-started events) and at most 16 min out.  Because the lower bound
@@ -31,7 +33,6 @@
  *   T-05-19 — per-subscription try/catch; dispatchPush already swallows 410/404.
  */
 
-import { schedule } from 'node-cron'
 import { and, eq, gt, lte, sql } from 'drizzle-orm'
 import { db } from '../db/client.js'
 import { calendars, calendarEvents, pushSubscriptions } from '../db/schema.js'
@@ -201,12 +202,14 @@ export async function runReminderCheck(now = new Date()): Promise<void> {
 /**
  * Start the 1-minute reminder scan schedule.
  * Call once from index.ts's isMainModule() guard — NOT at import time
- * (keeps the cron out of the test process; mirrors startBrokerPoller pattern).
+ * (keeps the setInterval out of the test process; mirrors startBrokerPoller pattern).
+ * Uses setInterval instead of node-cron: node-cron 4.2.1 silently skipped executions
+ * in the long-running server process; setInterval fires reliably.
  */
 export function startReminderScheduler(): void {
-  schedule('* * * * *', () => {
+  setInterval(() => {
     runReminderCheck().catch((err: unknown) => {
       console.error('[broker/reminderScheduler] Unhandled runReminderCheck error:', err)
     })
-  })
+  }, 60 * 1000)
 }