scheduled-tasks: schedule summary text drops days for multi-day cron (e.g. '0 8 * * 2,5' shows as 'only on Tuesday')

Description

update_scheduled_task / list_scheduled_tasks (the built-in scheduled-tasks tool) renders an incorrect human-readable summary in the schedule field when a cron expression specifies multiple comma-separated days of week.

Repro

1. Create or update a scheduled task with cronExpression: "0 8 * * 2,5" (intended: every Tuesday and Friday at 08:00 local time).
2. Call list_scheduled_tasks (or read the update_scheduled_task response).

Expected: schedule field describes both days, e.g. "At 08:00 AM, Tuesday and Friday".

Actual: schedule field reads "At 08:02 AM, only on Tuesday" — silently drops the second day (Friday) and mislabels a multi-day schedule as "only on" a single day.

Note: the underlying cronExpression ("0 8 * * 2,5") and computed nextRunAt are both correct — this is purely a display/formatting bug in the human-readable summary, but it's misleading enough that a user could reasonably believe their task is scheduled for one day when it actually runs on two (or more).

Environment

• Claude Code CLI 2.1.215, win32 (Windows 11)
• Installed via npm install -g @anthropic-ai/claude-code --prefix ... (standalone CLI)

Impact

Low severity (the actual schedule is correct, only the display text is wrong), but worth fixing since it undermines trust in the tool's own status output — a user checking "is this really running twice a week" gets a wrong answer from the tool itself.