Add Temporal Context

[mheadd]

Summary

Add Time-Relevant Information

type Park struct {
    // ...existing fields...
    
    // Temporal context
    CurrentSeason    string    `json:"current_season,omitempty"`     // "Winter", "Peak Season"
    SeasonalNote     string    `json:"seasonal_note,omitempty"`      // "Road closures common in winter"
    LastUpdated      time.Time `json:"last_updated"`
    NextMajorEvent   *Event    `json:"next_major_event,omitempty"`   // Ranger programs, etc.
}