Fix monthly weekly task appearing as due every day (#1266)

[zazer0]

Summary

Fixes #1266 where daily tasks set to repeat monthly on a specific weekday occurrence (e.g., "3rd Tuesday of every month") were incorrectly appearing as due every day instead of just once per month.

Root Cause

The bug was in TaskFormView.swift line 1049 (now line 1063). The code was using Calendar.component(.weekOfMonth, from: startDate) - 1 which:

1. Uses .weekOfMonth that returns which week of the month a date is in (1-6), not which occurrence of a specific weekday
2. Subtracts 1 to convert to 0-indexed values
3. Produces incorrect values, especially problematic when the month starts on the target weekday (resulting in 1 - 1 = 0, which is invalid)

Example of the bug:

• User selects January 1, 2025 (first Wednesday of the month)
• Old code: weekOfMonth(1) - 1 = 0 ❌ (invalid, causes server to miscalculate and show task as due every day)
• New code: weekdayOrdinal = 1 ✅ (correctly indicates 1st occurrence)

Solution

Use DateFormatter pattern "F" to get the weekday ordinal (1-5) which correctly represents which occurrence of that specific weekday it is in the month. This matches what the Habitica server expects in the weeksOfMonth array.

Changes

• Added Calendar.weekdayOrdinal(for:) extension method that uses DateFormatter pattern "F"
• Fixed line 1063 to use Calendar.current.weekdayOrdinal(for: startDate) instead of the buggy calculation

Testing

• Swift syntax validation passes
• Code follows the existing pattern used in TaskRepeatablesSummaryInteractor.swift which already uses DateFormatter pattern "FEEEE" for display
• Existing test TaskRepeatablesSummaryInteractorTests.swift:163-164 expects weeksOfMonth = [5] for "5 Tuesday", confirming server expects 1-indexed values (1-5)

Habitica User ID

@zazy0