- Add replay regression test suite covering irregular/jittered timestamps, identical/zero dt, inverted timestamps, large gaps, pause/resume timing reconciliation, manual seek, speed changes, and large datasets (144k points).
- Harden advancePlaybackIndex against non-finite/NaN budget and timestamp delta anomalies.
- Reset lastTimeRef and cap frameDelta in WebTelemetryReplayModal to eliminate sudden jumps on speed switching or background tab resumes.
- Guard group-ride creation with in-flight isSubmitting state and disabled submit button in CreateGroupRideModal; guarantee unique collision-free ride IDs across concurrent submissions.
- Remove obsolete Vercel reference in website/.env.example in favor of Vultr VPS and Caddy; add npm test script.