Restore MMR-based map circle colors while keeping risk badges

[gvegayon]

Summary

• Kept the new low/moderate/high risk badges for the table and city panels.
• Restored the map circle fill colors to the original MMR vaccination-rate scale.
• Swapped the map legend and subtitle back to describe vaccination-rate coloring instead of risk levels.
• Removed the visible low/moderate/high threshold text from the shared panel so it no longer appears on mobile or desktop.

Testing

• Parsed the inline scripts in docs/index.html successfully.
• Ran git diff --check with no formatting issues.