Add sorting and filtering controls to admin events page

[cbj0hns0n]

Problem

The admin events page currently sorts events with active ones pinned to the top, then all others by most recent scheduled time. With many active conversations, newly created future events appear well below the fold and require multiple "Load More" clicks to find.

There's also no way to filter by event type, date range, or status from the UI.

Proposed solution

• Add filter controls: status (active / upcoming / past), event type, date range
• Add sort options: scheduled time (asc/desc), created date, status
• Consider making the default sort more discoverable for newly created events

Context

Discovered while setting up a new event via the bot-based event setup flow. The event was created successfully but wasn't visible without paging past all active conversations.