Clean up documentation consistency

model/alert.go

@@ -42,7 +42,7 @@ type WeatherAlert struct {
 	Headline string `json:"headline,omitempty"`
 
 	Severity  string `json:"severity,omitempty"`  // e.g. Extreme/Severe/Moderate/Minor/Unknown
-	Urgency   string `json:"urgency,omitempty"`   // e.g. Immediate/Expected/Future/Past/Unknown
+	Urgency   string `json:"urgency,omitempty"`   // provider-defined urgency value
 	Certainty string `json:"certainty,omitempty"` // e.g. Observed/Likely/Possible/Unlikely/Unknown
 
 	Status      string `json:"status,omitempty"`      // e.g. Actual/Exercise/Test/System/Unknown

model/forecast.go

@@ -34,7 +34,7 @@ type WeatherForecastRun struct {
 	LocationName string    `json:"locationName,omitempty"`
 	IssuedAt     time.Time `json:"issuedAt"` // required: when this run was generated/issued
 
-	// Some providers include both a generated time and a later update time.
+	// Some providers include both a generated time and a subsequent update time.
 	// Keep UpdatedAt optional; many providers won’t supply it.
 	UpdatedAt *time.Time `json:"updatedAt,omitempty"`