Bug Description

When a cron job is created at a time that is not exactly on the scheduled minute (e.g., creating a 0 * * * * task at 13:19), the scheduler skips all subsequent executions until the next day.

Steps to reproduce:

1. Create a cron job with expression 0 * * * * (every hour at minute 0) at 13:19
2. The scheduler should execute at 14:00, 15:00, etc.
3. Instead, the scheduler jumps directly to 16:00 or later, skipping 14:00 and 15:00

Expected behavior:
The scheduler should find the next matching time slot after the task creation time and execute accordingly.

Actual behavior:
The scheduler calculates next run time based on creation timestamp rather than finding the next valid cron match.

Environment:

• OpenClaw version: 2026.2.1
• OS: Linux
• Cron expression: 0 * * * *
• Task creation time: 13:19 (not on the hour)

Workaround:
Manually recreating the task at exactly the hour mark.