sdk: actually no, let's store all relay urls together in the same kvdb key.

sdk/kvstore/interface.go

@@ -14,7 +14,9 @@ type KVStore interface {
 	// Close releases any resources held by the store
 	Close() error
 
-	// Scan iterates through all keys with the given prefix.
-	// For each key-value pair, fn is called. If fn returns false, iteration stops.
-	Scan(prefix []byte, fn func(key []byte, value []byte) bool) error
+	// Update atomically modifies a value for a given key.
+	// The function f receives the current value (nil if not found)
+	// and returns the new value to be set.
+	// If f returns nil, the key is deleted.
+	Update(key []byte, f func([]byte) ([]byte, error)) error
 }