bug: schedule advisory calls a month-restricted cron "daily", contradicting the frequency beside it

[naufalfx805-source]

While reading src/lib/cron.ts I noticed describeCron destructures the five cron fields but skips the month:

const [minute, hour, dayOfMonth, , dayOfWeek] = f;

So a schedule that is restricted to certain months gets described by its finer fields alone. runsPerMonth handles the month correctly (it divides by months.size / MONTHS_PER_YEAR), which puts the two halves of the advisory in direct conflict.

Reproduction

$ testsprite schedule create --cron "0 3 * 6 *" ...
This schedule will run ~3 time(s)/month (daily at 03:00). Each run is a full test run.

0 3 * 6 * runs daily at 03:00 during June only. "~3 time(s)/month" and "daily at 03:00" cannot both be true, and they are printed in the same sentence. This is the user-facing path — formatScheduleFrequencyAdvisory is called from src/commands/schedule.ts:245 (create) and :347 (update).

Confirmed against main (40d18d2):

cron	actual meaning	describeCron
0 3 * 6 *	daily in June	daily at 03:00
0 3 * 1,7 *	daily in Jan & Jul	daily at 03:00
0 3 * */6 *	daily in Jan & Jul	daily at 03:00
30 9 1 3 *	1 March, yearly	monthly on day 1 at 09:30

The existing tests miss it because describeCron is never exercised with a non-wildcard month, and the one advisory test that uses one (0 3 1 1 *) asserts only the frequency half, not the description.

Suggested fix

None of the phrasings describeCron can produce is able to carry "only in these months", so a restricted month should fall back to the raw expression — the same thing the function already does for every other shape it cannot state exactly, and what its docstring asks for: "a wrong description is worse than the raw expression".

I have the fix and regression tests ready (verified failing on main and passing with the change) and would like to pick this up — /assign.

[naufalfx805-source]

/assign

[testsprite-hob]

Assigned to @naufalfx805-source. Thanks for taking this on. (2 more slots available.)

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