Petrol Station skill completed, manifest updated

The Petrol Station skill has been completed and removed from the manifest. Team clarified scoring mechanics: scores reset when miners commit on-chain, model updates require new commits to reflect changes, and private track submissions have a 30-second timeout. Weights are set via the weights-setting loop with tiebreak logic available in the repository.

• •Petrol Station skill completed and removed from manifest
• •Scores reset on-chain commits; model updates require new commits
• •Private track: 30-second timeout, returns 0 if exceeded
• •Weights set via weights-setting loop with tiebreak logic in repo