fix(ui): fit the ride on a phone

[CodeDotJS]

Summary

• Add a text-size slider in Help, with compact type as the default on a phone.
• Split weekday and weekend fare into two chips, and on a phone place them just above the first and last train.
• Tighten phone padding and give the station circle a clear gap from the name.

Test plan

• Open the preview on a phone-width window at /, /map, /city, and /help
• Plan Welcome to Rithala and confirm the fare chips, the station gap, and the first and last train
• Confirm a wide window still shows weekday, weekend, stops, and changes in one row