Map auto-zoom

[jonathanstelman]

Epic 4: Frontend — Map

Auto-zoom the map to fit filtered resort locations.

Tasks

• When region/country/state filters change, auto-zoom map to fit filtered resorts
• Match existing zoom behavior from Streamlit app

Acceptance Criteria

• Selecting a region zooms map to fit all resorts in that region
• Selecting a country/state further narrows the viewport
• With no location filter, map shows full extent of all resorts
• Zoom uses padding so dots aren't at the very edge of the viewport