Bug Description

When updating cron jobs with timezone changes, the nextRunAtMs calculation occasionally produces incorrect values. Observed a 72-hour (3-day) offset where Friday was skipped to Monday.

Steps to Reproduce

1. Create a cron job with expression 0 8 * * 1-5 and tz: America/Los_Angeles
2. At ~10:35 PM CST Thursday, update multiple jobs in parallel (via tool calls) to change timezone to America/Chicago
3. Observe that one job gets incorrect nextRunAtMs (Monday instead of Friday)

Expected Behavior

Job with 0 8 * * 1-5 updated at 10:35 PM Thursday (CST) should schedule next run for Friday 8 AM CST.

Actual Behavior

• 2 of 3 jobs updated simultaneously got correct values
• 1 job (day-of-week constrained 1-5) got Monday Feb 9 instead of Friday Feb 6

Evidence

Direct testing with croner library returns correct result:

const { Cron } = require('croner');
const now = new Date('2026-02-06T04:35:22.877Z'); // 10:35 PM CST Thursday
const cron = new Cron('0 8 * * 1-5', { timezone: 'America/Chicago' });
cron.nextRun(now); // Returns Friday Feb 6, 8 AM ✅

But stored nextRunAtMs was 1770645600000 (Monday Feb 9, 8 AM).

Environment

• OpenClaw version: 2026.2.3-1
• OS: macOS Darwin 24.6.0 (arm64)
• Node: v22.22.0

Hypothesis

Possible race condition in parallel job updates, or state corruption during persist. The croner library is correct; issue is between library call and persisting result.