Epic 2: US 2.7 Handle recurring events

[kathrinmzl]

Epic 2: Event Management (for organizers)

US 2.7: As an organizer, I want to mark an event as recurring (e.g., weekly or monthly) so that runners can easily find regular meetups.

Acceptance Criteria

• Event creation/edit form includes a field for recurrence pattern (e.g., None, Weekly, Bi-weekly, Monthly).
• When viewing events, recurring events are displayed with their recurrence pattern.
• Filters still work correctly with recurring events (e.g., "This Week" shows recurring events if applicable).

Tasks

• Add neccessary fields to the Event model.
• Update event form to allow selection of recurrence pattern.
• Update views/templates to display recurrence info.
• Add tests to confirm recurring events are created, displayed, and filtered properly.