refactor: merge retry target type into http (max_retries=0 = fire-and-forget)

internal/database/database.go

@@ -92,6 +92,16 @@ func (d *Database) migrate() error {
 	}
 	d.log.Info("database migrations completed")
 
+	// Data migration: merge "retry" target type into "http".
+	// Previously there were two separate HTTP-based target types: "http"
+	// (fire-and-forget) and "retry" (with retries). Now "http" handles
+	// both: max_retries=0 means fire-and-forget, max_retries>0 enables
+	// retries with exponential backoff and circuit breaker.
+	if err := d.db.Exec("UPDATE targets SET type = 'http' WHERE type = 'retry'").Error; err != nil {
+		d.log.Error("failed to migrate retry targets to http", "error", err)
+		return err
+	}
+
 	// Check if admin user exists
 	var userCount int64
 	if err := d.db.Model(&User{}).Count(&userCount).Error; err != nil {