fix: 🐛 adjust button sizes so anteatery filter button doesnt cut out

[jkhlin]

Summary

I found the overflow source: each filter row is forced into a single horizontal flex row, so on narrow widths the three MUI buttons can’t fit and Anteatery spills outside. I’m updating both filter groups to responsive grids with full-width buttons on mobile so they stay evenly aligned and inside the box.

Changes

• Switched both filter button rows (Event Type and Location) from single-row flex to responsive grid
• Made each filter button full-width within its grid cell and reduced horizontal padding on small screens
• Each filter row now fills the available width
• This makes All Locations, Brandywine, and Anteatery visually closer in height to the Event Type row

Testing Instructions

Start PeterPlate
Open using mobile view or on mobile
Navigate to the Events page
Switch to Calendar View
Look at the Location filter buttons (on smaller screen sizes, the "Anteatery" button overflows outside the container box, while larger screen sizes display correctly)
Use responsive design and move around the width to test all possibilities of screen sizes

Closes #660