County Sprints frontend/leaderboard update

Replace these files in the project:

• src/main.rs
• src/model.rs
• src/db.rs
• src/leaderboard.rs
• src/web.rs
• migrations/0001_initial.sql

No change is required to the working src/intervals.rs.

The existing src/webhook.rs can keep calling:

crate::process_activity(state_clone, athlete_id, activity_id.clone()).await

process_activity() now loads the athlete's OAuth access token itself. The development sync uses the explicit API-key client, so the personal development key is not written to the database.

Database

The migration is intentionally a complete replacement because the database can be reset during development.

The new schema adds:

• leaderboard_groups
• leaderboard_group_members
• indexes for activity/crossing queries

Leaderboard location matching

Leaderboard rows are grouped by:

• 10-minute time bucket
• source county
• destination county
• spatial cluster with a 10 metre DBSCAN radius

The crossing geometry is transformed to EPSG:3857 before the 10 metre clustering calculation so the distance is measured in metres rather than degrees.

Frontend

The frontend now provides:

• Leaflet map for each leaderboard group
• small map for every individual crossing
• activity detail page at /activity/{activity_id}
• activity map containing all crossings
• browser-local timestamp formatting using Intl.DateTimeFormat
• leaderboard group management at /groups
• group selection on the main leaderboard

The map uses Leaflet and OpenStreetMap tiles. Leaflet's current stable 1.x documentation describes the same map/tile-layer APIs used here. citeturn0search2turn0search9