v0.62.4

Fixed

• CalDAV outbound sync now generates RFC 5545-compliant datetime strings. Previously, parseTimeInput returned HH:MM (no seconds), and the ICS builder produced a 4-digit time (HHMM) instead of the required 6-digit HHMMSS format. Strict CalDAV servers such as mailbox.org rejected the invalid value and defaulted the event time to 00:00 (#246).
• All-day events synced to CalDAV now use DTSTART;VALUE=DATE and an exclusive DTEND per RFC 5545, instead of being treated as timed events at midnight (#246).
• Outbound CalDAV ICS now includes DTSTAMP, LOCATION, and RRULE fields, and handles missing end_datetime gracefully (#246).