Fix: roza -a fails after setting --first-roza-date

[Copilot]

When --first-roza-date is set, roza -a and roza --number N use fetchCustomRamadanDays which fired 30 parallel requests to the AlAdhan API — one per Ramadan day. This saturates the API's rate limit, returning non-standard error responses that fail Zod's ApiEnvelopeSchema validation (code field missing → "Required"), causing all three fallback methods to fail simultaneously. Without --first-roza-date, roza -a uses a single bulk Hijri calendar call and never hits this limit.

Changes

• fetchCustomRamadanDays rewritten to use the Gregorian monthly calendar API (calendarByAddress / calendarByCity) instead of 30 individual timing calls. A 30-day Ramadan period spans at most 2 calendar months, so this reduces the call count from 30 → 1–2.

• fetchGregorianMonthCalendar added — mirrors the fallback chain pattern of fetchRamadanCalendar (address → city).

• toApiDateString added — formats a Date to DD-MM-YYYY to match AlAdhan API date keys used for day lookup after fetching the monthly calendar.

// Before: 30 concurrent requests → rate-limited
return Promise.all(days.map(dayDate => fetchRamadanDay(query, dayDate)));

// After: 1–2 bulk monthly calendar requests
const monthCalendars = await Promise.all(
  uniqueMonths.map(({ year, month }) => fetchGregorianMonthCalendar(query, year, month))
);

• api.test.ts: added test for fetchCalendarByAddress.

Original prompt

---

This section details on the original issue you should resolve

<issue_title>Bug: Prayer times not fetched after changing the first date</issue_title>
<issue_description>## Description

After changing the first date, the application fails to fetch prayer times.
This happens even though the same configuration works before the date change.

Error Output

roza -a

✖ Could not fetch prayer times. timingsByAddress failed: Invalid API response: Required | timingsByCity failed: Invalid API response: Required | timingsByCoords failed: Invalid API response: Required

</issue_description>

Comments on the Issue (you are @copilot in this section)

@ahmadawais Try resetting.

Feel free to send in a PR.

• Fixes Bug: Prayer times not fetched after changing the first date #27

---

✨ Let Copilot coding agent set things up for you — coding agent works faster and does higher quality work when set up for your repo.