Add Fortnightly Frequency Option to Messaging Rules

Feature Request: : Currently, messaging rules using "On a given day of the week" only support weekly frequency ("every Monday") or first occurrence options. This doesn't work for fortnightly schedules like bin collection that happens every 2 weeks.

Requested Solution: Add a fortnightly frequency option to messaging rules, allowing hosts to send messages every 2 weeks on a specific day (e.g., "every 2nd Monday").

Use Case: Bin collection reminders, property maintenance notifications, or any recurring guest communication that happens bi-weekly rather than weekly.

Using task rules for team notifications (which do support custom frequencies) but we want to be able to message guests. The use case is basically that if guest is has been staying a few nights then ask guest to take out trash if they decline and then message team members to complete the task